Redline
by renegademechanic
Summary: Mikaela wants to practice driving stick, but what happens when an attractive Autobot leader is your instructor? Mikaela/Optimus Prime
1. At Mike's

_A/N: as stated in the description, this fic will focus on the pairing Mikaela/Optimus Prime, and a driving lesson they share with surprising results._

 _'Surprising results' being of a sexual variety, so if that isn't your cup of tea, this is your warning. Also, I may have a small (or not-so-small tbh) infatuation with big diesel trucks which, well... does not exactly make me any less fascinated Optimus Prime's alt-form... (like he wasn't already super hot WITHOUT having a gorgeous alt-form). So, disclaimer- just in case it was not already implied strongly enough, this story contains awesome alt-mode sex. Because heck yeah, why not?_

 **Redline**

.

 **Part 1**

 _~One month before the events of Revenge of the Fallen_

Friday nights were poker nights at Mike's Custom Cycles. Most nights, Mikaela had better things to be doing than sitting around a poker table with a bunch of smelly old men who loved motorcycles too much, especially as they were almost always hosted in the cramped, cluttered office that really was no better than the disorganized workshop.

The whole place was constantly filled with the strong smell of stale beer, tobacco smoke, and the ever-present undertone of mechanical grease and car exhaust. Haze hung heavy in the air on such evenings, wafting over the heads of the participants from the endless chain-smoking of cigars and cigarettes, the smoke yellow in the dingy light coming from a collection of desk lamps set-up to illuminate the cardtable.

It was a depressing place to be, and this was why Mikaela avoided them (because who wanted to be at work after hours, anyways?), but gambling had always been a part of her father's life. Gambling on the weekends in messy offices of motorcycle shops, or gambling with their lives, it didn't matter which—there were only three things in life that her father really loved. Thrills, cars, and Mikaela. And Mikaela loved him, too—she loved her father a lot, even though he got on her nerves, sometimes.

So, when the occasional Friday night rolled around where Mikaela found herself with nothing to do—those rare times when her girlfriends were all out with their boyfriends, and Sam's parents had grounded him for forgetting to call when he was over for a sleepover at Mikaela's so that they knew he hadn't gotten himself abducted by aliens again—she'd always accept an invitation from Cal and the boys to one of their boring, smelly poker games.

Looking back, she supposed that was how it all started.

Because if she hadn't found herself pulling up to Mike's on that fateful Friday night with Cal, she would have been with Sam; and if she had been with Sam, maybe she wouldn't have been so worried about things.

Or maybe, it had started before that. Maybe it had all happened because they'd all been talking about Christine. And because they had talked about Christine, she had started thinking about Bee, and because of that, she had remembered the day that Sam and her had first met and that had just made everything worse.

That had been the day when _everything_ had started. The first time she had ever laid eyes on Sam Witwicky—that she could remember, at least—had been the day that her life was destined to change forever.

Although… it was true that she only got in the car with him in the first place because of Todd. And Todd _hated_ Christine.

The summer of '09 was unusually hot, even for the south. The great desert plains that stretched for miles around the great city had been transformed into a wide, cracked dust bowl, complete with armies of tumbleweeds; even in the center of the urban sprawl, you'd have been hard pressed to find someone who wasn't suffering in some way from the heat. Only employees who worked in tall, air-conditioned office buildings with adjoining underground parking, who lived in ritzy skyscrapers had the fortune of totally avoiding the scorching temperatures. Everyone else, however, had to find other ways of keeping cool—men in blue-collar business suits could be seen running to and fro with newspapers held over their heads for shade, bums sat in reclusive cement corners that hardly saw the light of day, and Sam's family had taken a much-awaited weekend trip to the coast.

This was the reason that Mikaela found herself at home alone with nothing important to do on a particularly gorgeous Friday evening. Sam had not even asked her if she would have liked to go along with his family—in his defense, all of Friday evening and the last half of Sunday would have been wasted driving, and the whole point behind the trip was so that Sam could get a feel for the college he planned to attend come September. Her coming along might have been kind of intrusive in that way—but she _was_ his girlfriend of almost two years, and it was starting to feel a little like Sam cared more about college than he did about her.

They'd had a bit of an argument about it before he left, actually. They seemed to be doing that more and more, these days, and it made her feel sad. It didn't help that their time together was growing increasingly scarce; Sam was leaving for college and Mikaela had a job. Her father was out of prison now, too, and she had to take care of him. Some part of her was aware that Sam was kind of jealous—not only because a lot of her time that was usually allotted for him was now taken up by Cal and work, but she knew that it bothered him that he was almost nineteen years old and still had never had a job.

But that didn't mean he could get away with being a jerk about it whenever he pleased. Mikaela was hurt that he'd left her behind, but at the same time she wasn't going to let it ruin her weekend—it was her birthday the coming Saturday, and she wanted to make the most of being eighteen while it lasted.

It was Cal who had convinced her to come out for a couple of rounds of Texas Hold 'Em and maybe a drink or two if she felt like it. Naturally, she wasn't able to ride her bike if she was going to have a drink, so she carpooled with Cal—he'd rescued this cherry-red Plymouth Fury from a junkyard a couple weekends ago, and that was why they'd started talking about _Christine_.

"It's basically Christine," Mikaela had told Cal, having been a fan of the movie based off of the Stephen King book for as long as she could remember.

"It's not Christine. It doesn't even look like her, Mikaela. This thing is a hunk of junk."

"Whatever you say, Cal. Let's just hope this thing doesn't try to kill us."

She had been kidding, of course. The real Christine was a sentient, very murderous fictional car that had the ability to miraculously repair almost any kind of damage you could think of—but Mikaela still shot a wary glance at the dashboard.

There were just some things in life that you couldn't go through without becoming a little bit vigilant, sometimes. Just in case. And finding out that there were aliens disguised as vehicles situated all around the globe—some of them actually outright murderous ones—had come as quite a shock, and she wasn't about to forget it any time soon.

Nevertheless, the car did seem to be just a car—as far as Mikaela could tell, anyways.

The subject had come up again around the poker table. Mikaela had been dealt a two and a three of hearts—Tammy, Mike's wife, who had very curly, greying blonde hair and spoke with a thick Russian accent, was dealing. She sucked on the end of a long mahogany pipe as she dealt the flop—a red ace, a black queen, and a red seven—before she put down the pipe and turned to Cal.

"I almost forgot, zat is a nice find you haf parked outside, Cal. Whare did you get zuch an old beast?"

"Al's," said Cal, meaning the auto wrecker down the road. Mikaela's eyes met her father's. "Bought and paid for by me. It certainly has an aesthetic to it—Mikaela says the damned car's Christine. You know, from that 80's movie."

"Well you never know," muttered Mikaela.

A shout of laughter went around the table.

"Oh, amuzing," cackled Tammy, slapping Mikaela on the arm. She scowled. "Zat car is just a regular car. Zare is no such fing as a car zat is alive, you zilly girl."

Everyone around the table laughed again, but Mikaela didn't join in. It was always when people who didn't know, people who were ignorant to the existence of the war of the Autobots and took their daily lives for granted— _civilians_ —that thought that the idea of a sentient killer car was some kind of joke or something to laugh about. It made her feel really awkward.

It was incredible to think she had once enjoyed the movie _Christine_ ; just the thought of it sent shivers up her spine, now. It made her remember the decepticons… but then, there were the Autobots, too. And the Autobots were good—Bee had become a very close friend of hers over the past two years for a reason. It was a shame that they had to be kept a secret, but it was necessary. The reaction of the adults around the poker table was enough to prove at least partly why that was so.

But, deep down she really hoped that things would be different someday, and that the humans and the Autobots could one day coexist peacefully, sans decepticons. Because right now, she was fast approaching a place where she genuinely felt like nobody understood at all, save for the Autobots themselves, witnesses of the battle of Mission City, and Sam—and Sam was not going to be around anymore come September.

"Mikaela, honey?" came Cal's voice, drifting through her thoughts. "It's your turn to bet."

She had been trying hard to stay interested in the game, but she was beginning to find it incredibly dull. And above all, she really missed Sam.

"I think I'm gonna take off, Cal," she told her father after she'd checked and had nil on the river, "You can have these, I don't want them." She pushed the small pile of chips away from her.

"Okay…" he looked confused, but accepted the poker chips regardless. "You okay to get home on your own, Mikaela?"

"Yeah, don't worry about it." Pushing in her chair, she tried her best to smile warmly at her boss and the other figures around the table but her voice was growing increasingly croaky from emotion and the thick smoke that was hanging about the place. "Thanks again, guys… I'm just feeling a little tired, that's all…"

"Okay. Call me when you get home, all right?"

"Sure thing, Cal."

The tinkle of the doorbell was the last thing she'd heard before the sounds of laughter and the gentle clink of poker chips coming from the old office were cut off, and Mikaela stepped out into the half-full parking lot. The first thing she noticed was how extremely lonely she felt, now that she was no longer surrounded by a room full of people. While she had been inside, her chest had felt tight and claustrophobic—but out here, she could breathe easier, and there was nothing to distract her from the fact that she was completely and totally _alone._ The world was dark and empty—the sun had set hours ago and overhead was a velvety, infinite expanse of star-strung sky— _empty—_ and the heat of the day had not yet fully dissipated, leaving the air feeling humid and stuffy.

She hiked her purse higher up onto her shoulder, breathed in a deep, steadying breath, and began what was surely to be a very quiet journey home.

It was no more than half a mile's walk. Mike's shop was located nearby a twenty-four-hour truck stop at the edge of a big clover-leaf freeway junction between the Interstate and a local highway—the bright lights from the overpasses behind her shone white, casting a long shadow as she entered the narrow alleyway that would take her into the residential neighborhood beyond. On one side, it was lined by the truck stop's parking lot, and a rusted chain-link fence ran along the curb here, marking the property line. On the other side of the laneway was a line of messy, un-cared for hedgerows.

The pavement was broken and full of potholes, so Mikaela walked with care, the _clack, clack_ of her high heels making some of the only sounds in the night. The only other noises were the rumble of distant traffic on the Interstate exchange, and the slamming of someone's car door a few blocks away. Someone's dog with a very yappy bark yipped several times in reply.

It was so quiet—a summer night's breeze swept through the alley, rippling her hair and thin t-shirt, and still her thoughts drifted to Sam again. She hoped that he was having fun wherever he was—god, she missed him. They could still do goodnight phone calls and all of that, but it just wasn't the same. They'd have to think of an even better way to keep in contact while he was at college. She pulled out her phone to send him a text letting him know that she was just about home from Mike's, wondering if he was still awake, when something happened.

It was no more than a prickling feeling at first—the unholy, creeping sensation that someone was watching her. The wind gusted again, and shadows flickered among the messy hedgerows beside her—was there something inside of the bushes? Or was it just the wind that was making her feel this way?

Mikaela made to turn around nervously to check that she was still alone—but as she did, there was an immediate blinding flash and the laneway was filled with light. Frightened and unable to see, Mikaela tripped on a pothole, twisting her ankle a little. Her purse fell to the ground, and it was all she could do to not fall over with it.

Her heartbeat stuck inside of her throat. Mikaela saw that two twin headlights were making their way slowly toward her, accompanied by the deep rumble of a revving engine and the crackling of gravel under the tires as the vehicle rolled forward. Her first thought was _oh God, Decepticon,_ but as the car passed underneath the closest streetlamp, its paint job was suddenly illuminated, and she realized that it was a very shiny yellow-and-black Camaro with black racing stripes. She gasped—" _Bumblebee_?"

The Camaro flashed its highbeams at her and stopped a few meters away, idling lowly. The driver's side door swung open in the darkness, waiting.

"How did you _find_ me?" Mikaela asked the car as she approached, sitting down inside gratefully. "It's almost one o'clock in the morning—you scared the crap out of me, Bee."

"I had a feeling—are you okay, man? That looked like it had to hurt—" the Camaro's speech was nothing more than a few random broken voice recordings played low over the radio.

"Oh, I'm fine," said Mikaela, rechecking that everything was still inside of her purse, which had been retrieved from the pavement. "My ankle is a little sore, but it'll be fine." She patted the dashboard affectionately as she settled into the seat. "What're you doing here, though?"

"Aw, I'm sorry," the recording sounded regretful before he added some of his own speech. "Sam's gone, 'n someone's gotta watch over you, kid. Where are ya headed?"

"Well, I was on my way home, but…"

"But what?" the Camaro asked.

Mikaela grinned. "Well since you're here… it's Friday night, and I'm starving. Would you mind hitting a Taco Bell on the way home? You don't have to…" she always felt weird asking Bee for rides places. She hardly ever did, and she knew that he really didn't mind, but she was a very independent person and was perfectly capable of driving herself places on her own. "I just thought it might be cool to hang out for a bit. It feels like it's been forever since the last time we stayed up late together."

"No problem-o, buddy," said Bee, playing a recording that sounded very much like it had come from a Yankee cab-driver as he revved his engine and Mikaela saw the accelerator pedal move of its own accord as the Camaro's tachometer spiked, and she knew that he was excited. Night driving just happened to be a pastime the human and the Autobot shared a passion for. "We'll be there in a jiffy—buckle up, sweetheart," he instructed, still as the Yankee cabbie.

She did so, feeling a lot better now that she was no longer alone. It was Friday night, on the most beautiful weekend of the summer so far—and if she couldn't have Sam for company, well, at least she had Bee. Bumblebee was definitely the next best thing.


	2. A Midnight Drive

**Redline**

.

 **Part 2**

Cars were in her blood. Growing up, Cal had taught her as much about mechanics as a single father raising a little girl could. He'd always said that a woman who could fix a car was a woman who could take care of herself—and he'd always wanted Mikaela to be able to do just that. Almost all of her best childhood memories involved cars in some way—after all, Cal loved them, and with time she grew to love them, too.

The first time she'd ever fallen in love, she used to say that it was with the mint '65 SS Camaro fastback that one of their neighbors had procured by some (most likely undesirable) means. There was something about the exhilarating rumble of the supercharged big-block under that cherry-red Chevy hood that made her knees shake even more than they had back when good old Trent had first flashed her his dazzling smile back in sixth grade.

She'd been so naïve back then, so afraid that her peers would learn the truth about her home life and condemn her. For years she'd felt like that. It wasn't until she met Sam and the Autobots that things had begun to change a little bit. It was hard to feel like a freak because you knew too much about cars when it was the cars themselves who were your best friends.

But it had been that good old cherry-red Camaro that had been on her mind when Sam had saved her from an extremely long walk home from the lake with Trent that fateful afternoon—Bee had reminded her of how sexy she used to find that car, and how much she'd longed to drive it. It was embarrassing to admit that she'd found Bee a little bit sexy too, at first, now that she knew what Bee was—but she would be lying to herself if she tried to deny that she'd felt kind of turned on when she'd opened his hood.

He was powerful, and raw, mechanical power was _dead_ sexy.

But now that she was aware that he was actually a giant robot? Not so much. And not for the typical reasons another girl may have mentioned for being weirded out about it, like him being an alien and all—but instead, it was because she had the utmost respect for Bee. That didn't stop Sam and her from making out on top of him once or twice, though. Sam had pinned her down against the hood, and she still didn't know if he'd pressed the small of her back right into the vibration and warmth on purpose or not—it didn't matter. The point of it was that it _did_ things to her when he did that, and she liked it. She liked it a _lot._

The thought of it was making her feel a little warm, so she cracked the window and relished the feeling of the night air blowing on her face as they drove together. Her loneliness had mostly dissipated now that she was with Bee. Bee turned right onto Monroe Street, heading further into the financial district of the city where all of the twenty-four-hour fast food joints were located—but underneath it all, she still did miss Sam. He hadn't texted her back—she supposed he was already asleep—and he wasn't going to be home until late Sunday night, she was sure. That would mean no sleepovers anytime soon, not until her birthday next Saturday at the earliest.

And speaking of her birthday, with a pang she remembered that Sam hadn't even mentioned it to her yet or asked her what she'd wanted.

"Are you okay, kiddo? You're real quiet tonight," Bumblebee intruded into her thoughts, forgoing the usual use of radio clips in an effort to sound more serious. It was always so weird to hear him use his actual voice—Optimus had fixed his vocal processor a while ago, but the bot had become so used to using radio recordings that it was hard for him to break the habit sometimes. That, and Mikaela had a distinct feeling that Bumblebee had a little too much fun with them.

"Mmm," murmured Mikaela. "I'm okay. Just thinking."

"'bout what?"

"Sam. I was just wondering about something…" she paused, wondering how much of what she was thinking she should say to Bee. "Did he—do you know if he remembers that it's my birthday next Saturday?"

It was a mark of how distant Sam and hers relationship had already become that she even had to ask him that question. Too late, however, Mikaela realized that Bee probably wouldn't know—he had said that he had something really important planned with the Autobots on that weekend, so Sam was going to be without a vehicle and if he _had_ planned anything yet, he probably would not have told Bee for that reason.

Bee played a celebratory recorded chorus of 'Happy Birthday' which ended in applause and cheers before he answered. "Oh, yes," he told her, "But it's a surprise!"

Mikaela's head snapped down to stare at the stereo so fast that it hurt. "Whadd'ya mean it's a surprise, Bee?" she demanded. "Sam hasn't _seriously_ —I totally thought he'd just forgot—"

"Sam, forget about you?" Bee laughed. "Nah…"

"Well, he's been so busy, lately," she mumbled, staring at the floorboards.

"Wait…" said the Camaro in disbelief. "You actually _did_ think he forgot about you, didn't cha!"

Mikaela sniffed. "Well, yeah," she said. "He…"

She hesitated. Bee and her were close, it was perfectly true—but Mikaela really wasn't the sort of person to go around spilling the beans about her internal feelings and personal life. Even with Sam, it had been a hurdle they'd had to find a way to overcome, more or less—the sinking feeling in her chest sharpened when she thought about it.

She felt guilty—here she was, whining internally about how Sam was away all weekend and that he'd probably forgotten about her birthday, meanwhile for one, she knew deep down that it was necessary for him to go away this weekend to prepare for college, and two, he actually _hadn't_ forgotten about her birthday. Not according to Bee, at least.

Mikaela was saved from finishing the rest of her sentence by the gentle _bump_ of the Camaro's suspension bouncing over the twenty-four-hour Taco Bell drive-thru's parking lot entrance. There was one car in line ahead of them, so Mikaela took the opportunity to look at the menu, and decided that she would have a Number One combo with a Coke. Fast food was not usually her thing—Mikaela liked to eat as healthy as she could—but there was something to be said for late-night trips to fast food joints. They had a certain aesthetic, and the city around them was so beautiful by night.

Mikaela received her food and Bee parked. The familiar skyline of skyscrapers and office buildings overhead was dotted with jewel-bright, mirror-glass windows, each reaching right up to meet the twinkling stars. Down in the streets was a neon kaleidoscope of epileptically-blinking colors, and many pub-goers and late-night wanderers navigated dirty sidewalks beneath these displays, visible as only shifting shapes of black with clouds of smoke wafting over their heads as they chattered and laughed drunkenly. Over the sound of their voices, bass thumped through the vacant alleyways from underground bars. And the smell—the smell of the city, of car exhaust and cooling asphalt, concrete that had baked all day in the sun was only partially overwhelmed by steaming hot, late-night grub, coming from everything greasy and deep-fried but oh-so good.

Mikaela had watched this display in silence while she ate her burrito. It was satisfyingly fabulous-tasting.

It wasn't until she'd finished that her mind drifted back to Sam. She took a long, thoughtful sip of Coke before addressing Bee.

"Can I tell you something secret?" she asked the Camaro.

"Anything, m'lady," he replied with a recording that she'd recognized but could not think from where.

Mikaela weighed each word carefully as she spoke. "Sam and I have never told each other 'I love you'."

Bee was silent for a minute Mikaela immediately regretted saying this, thinking she'd made things awkward again. Before he answered her, he turned his engine over, and she felt the sudden thrum of power through the seat.

"Sam does love you," Bumblebee said, uncharacteristically quiet and serious.

The feeling of guilt increased in Mikaela's stomach. She knew that the young Autobot was not one for these types of conversations. It was a mark of how much their friendship had grown over the past years that Bee was not joking around and being silly—he could tell that his friend was hurting, and as a result, he was remarkably subdued.

"I'm sorry, Bee, I shouldn't have said anything. I didn't—"

"It's okay," said Bee sadly as they pulled out of the parking lot and started off toward Mikaela's house. "Don't worry about it."

Mikaela bit her lip.

The rearview mirror readjusted of its own accord. "Really!" Bee insisted.

Most of the ride home passed in silence—Bee played a couple of upbeat songs he knew that she liked, and Mikaela hummed along. It was getting to be so late that they'd hardly passed anyone on the roads. The outskirts of the city could be like a ghost town at night, even on the weekends.

As they passed by a block from Mike's, Mikaela glanced down a darkened side-street that ended in the Cycle Shop's parking lot to see if Cal was still there—but the shop's windows looked dank and dark in the distance and the parking lot was empty. They rounded the corner to where the alleyway was where Bee had scared her earlier, and through the chain-link fence Mikaela caught the bright glow of the familiar truck stop. Almost all of its bays were full with semis decked out in colorful lights, their drivers valiantly pumping diesel in the dead of night. It was the only proof in the tiny neighborhood that the outside world was still alive.

"You know, Bee," Mikaela said thoughtfully as she watched the truckers, and Bee automatically turned down the music to listen to her, "I used to think it might be kind of cool to drive truck one day."

Bumblebee chuckled. "Don't let Prime hear you say that."

Mikaela scoffed and laughed a little herself. "No, really, Bee. I mean, it's kind of—you'd get paid to drive, and all, and I've always really liked driving. Some of the times I've felt the most at home was behind the wheel," she explained.

 _And plus_ , she thought to herself, although she'd never dare to say something like this aloud to Bee, _They're some of the biggest beasts on the road…_ they were intriguing, but she didn't know much about them as Cal's interest in trucks did not really go past your typical pick-up.

"Well, maybe you should learn," suggested Bumblebee.

Mikaela sighed and leaned back into the seat. "I don't know, Bee," she said sadly. "Things are just so crazy right now. I don't know what's going to happen tomorrow, let alone in the future. Two years ago I had no idea that you even existed, Bee. So much has changed since then and I just haven't got time to even think about doing something like that anymore, you know? Plus, Cal needs me."

"I guess," said the Autobot thoughtfully before shuffling his radio onto a fairly jazzy, upbeat song that Mikaela knew all the lyrics to. She couldn't help but sing aloud.

" _'Cause the world might do me in_ _  
 _It's all right 'cause I'm with friends_  
 _I guess I'm givin' up again_  
 _It doesn't matter, oooh—_  
 _Had me feelin' like a ghost_  
 _And that's what I hate the most_  
 _Guess I'm givin' up again_  
 _This time, this time I might just disappear…__ "

The song was still playing as they pulled into Mikaela's driveway. No lights were on, so she assumed that Cal must already be in bed. "Thanks for the ride and the food, Bee," she said with a half-hearted grin, squeezing the Camaro's steering wheel once in goodbye as Bee parked and shut off his headlights so that they didn't shine into Cal's bedroom window and shut off the music.

"No problem." Bee unbuckled her seat belt for her. Mikaela unlocked the driver's door and opened it, but before she could climb out, Bumblebee had stopped her. "Hold on one second..."

She waited. She felt the Camaro wobble a little on his chassis, although he was squirming uncomfortably. She knew Bee, and unless her imagination was getting the better of her due to lack of sleep (which was possible, she thought as she yawned deeply, suddenly exhausted), her friend was going through some kind of internal battle about something unknown.

"About that birthday surprise Sam has for you…"

Mikaela froze. She knew that, although Bee was an extremely loyal friend, he sometimes had a hard time keeping secrets that he was really excited about. He'd never tell anything that _really_ mattered, but stuff that he found insignificant in the grand scheme of things, and stuff that he knew everyone would benefit from if they knew, was what he had the most trouble with. He was a little bit too carefree sometimes, but he always had the best intentions. He just lacked the self-control not to be a little bit of an instigator.

Yet again, the little Camaro had found himself in a position where he just couldn't control himself. His best human friend had told him an important, cool thing he was going to do for his girlfriend's birthday, and he couldn't help wanting to tell her—Sam wasn't in town, so there was nobody else around to cheer said sad girlfriend up, was there?

"He's gonna take you to Vegas," Bee squirmed.

Mikaela's mouth opened of its own accord. Sam _hated_ Las Vegas. Why did he want to take her somewhere he hated?

"And that's not all," said Bee, committed to telling the whole thing, now. "He's going to rent you a _car_ …"

"A car?" Mikaela frowned. "But I've already got—"

"I know. Not just _any_ car, Mickey," he said, using the affectionate nickname for her that he only very rarely used. "He's gonna rent you your _dream_ car..."

Mikaela was shocked. "Not the Camaro?" she gasped.

" _Is_ it a Camaro?" She could almost feel the robot grinning smugly at her. "Damn, I didn't know you had a thing for us..."

" _What_?" Mikaela choked, laughing. "I—I don't have a—wait a sec, are you _flirting_ with me, you goddamned weird-ass robot?"

She punched the top of the dash playfully, and Bumblebee apologized. "Sorry," he said. "I'm just expressing my… _appreciation_ … that Sam found himself a girl that likes 'em. Sam didn't say what make and model when he told me, just that it was a red manual shifter that could easily drive just about as fast as _I_ could. Yeah, right!"

Mikaela snorted in spite of herself. "Hang on," she said seriously, as part of what Bee had just told her sunk in. "Sam can't drive a stick."

"Yup. You're going to have to drive."

She stared at the radio. "Shit," she muttered, more to herself than anything.

"What's wrong?"

"Uh, nothing." Her face was burning as she tried to avoid Bee's eyes—problem was, she wasn't exactly sure where they were located in his vehicle form.

The truth was that Mikaela had not driven a standard in a very long time. In fact, the last time she had driven standard had been so long ago that she had not done it legally—back when her father still used to steal cars, he'd taught her to drive without her license in case she'd ever needed to take over for him. But most cars they'd ended up boosting had been automatics, and so had all of the vehicles Mikaela had owned so far—while Cal had grown up in an era where manuals were popular, it was much harder to come across a standard transmission in the millennium. Automatics were just in higher demand because they were easier to drive, and she wasn't even sure if she could run a standard anymore, it had been so long.

"What's the matter?" Bee asked again, and she knew that she couldn't lie to him. He'd been honest with her, after all. "'Con got your tongue? Come on, you can tell _me_!"

"Okay, okay, fine," said Mikaela uncomfortably. "It's just that, uh, it's been an awful long time since I've driven standard."

"So?"

" _So_ , I'm probably shit. I don't think I remember at all actually, and that is _so_ embarrassing, coming from me."

"Hmm," said Bumblebee thoughtfully.

"I wish that there was some way for me to practice," she sighed, falling back into the seat. "The last thing I need right now is for Sam to rent me this beautiful car, only for me to have to tell him that I suck at driving stick. It would probably crush him."

Both of them sat in silence for a minute before Mikaela stifled a huge yawn.

"You should go inside and sleep," said Bee. "But, huh. Tomorrow's Saturday, right?—do ya know if you've got any plans, yet?"

"Not really." She had been thinking of heading over to the air-conditioned mall for a little shopping with some girlfriends she hadn't hung out with all week, but she'd only decided to do it because she had nothing better to do—it _was_ usually something she did enjoy a lot, but with Sam gone, the prospect didn't really make her feel all that excited. On the contrary, thinking about it was starting to make her feel empty and lonely again. "Why—did you have something in mind, Bee?"

"Kind of," he answered. "I have to go with the other 'bots back to NEST. Do you want'a tag along?"

Mikaela smiled at the thought of visiting the Autobot's main home again. She had been on base only once or twice since Mission City had happened—always with both Bee and Sam, and usually there hadn't been time to have a look around, or anything. She was a civilian, after all, and would not have even been granted access to base if it hadn't been for Bee—and as such, strict security measures applied to her.

She didn't mind, though. It was kind of cool, just to be allowed to be on site at one of the most secret and important military institution currently in the entire country. Visiting NEST was never boring, that was for sure.

"All right!" Mikaela answered eagerly. "That sounds sweet, Bee, I'd love to!"

And so it was decided. The two set a time for her to be picked up, said a happy ' _good night, see you in the morning_ ' to each other, and Mikaela climbed smoothly out of the Camaro. She was still smiling as she walked up the short pathway that led to the front door, and stopped on the doorstep to rummage in her purse for her keys. She heard the sound of Bee's engine turning over as she found them, and she opened the door, spinning around just in time to see the shiny vehicle pulling out of her driveway. She waved enthusiastically.

The Camaro flashed his highbeams once in farewell before turning up the street, undoubtedly heading back to Sam's empty driveway to sleep. Mikaela watched him go until he was out of sight, and yawned again. The door closed quietly behind her and she paused for a moment, leaning against it, listening to the pleasant silence of the house, thinking…

She still missed Sam, and she was still nervous about what the future had in store for their relationship, but… something inside of her felt a little less heavy than it had a couple of hours ago—a little _better_ , somehow. Maybe tomorrow wasn't going to be such a bad day, after all…


	3. Hitting the Road

**Redline**

.

 **Part 3**

Mikaela hadn't gotten to sleep until two in the morning. She'd taken care not to wake up Cal, but Bonecrusher was hyper and whining loudly at the sight of her, and had slobbered and jumped all over her as soon as she'd got in the door. After letting him out for a pee and giving him something to eat so he'd shut the hell up, she put on her pyjamas, brushed her teeth, and went straight to bed.

She had fallen asleep immediately, but it had felt like she had just briefly closed her eyes before she was awoken by the steady buzzing of her alarm clock. She groaned and reached out blearily to shut it off, almost knocking it over in the process.

She was _not_ a morning person.

Climbing out of her comfy bed was difficult, but a glance out the window showed her the beginnings of what was sure to be another scorching, beautiful day—already, the sun beat down onto the weathered asphalt, frying the yellowing lawns on both sides of the street. Mikaela had always thought it was a miracle that grass could survive in Nevada during summertime in heat waves like this to turn green in the winter again—it was always so strange when the rains rolled around and made everything grow again. It looked like a different world.

Mikaela sent Sam a quick good-morning text telling him what her plans for the day were before she jumped straight into the shower. The water was cool and refreshing and she squirted a blob of her favorite, lavender-smelling shampoo into her palm and lathered up, scrubbing rigorously.

Her thoughts drifted to the coming day as she washed, wondering what she should expect. Although visitation at NEST was supposed to be under strict, very boring protocol, it was the Autobots themselves that made every visit unique with their interesting personalities. The last two visits her and Sam had had been week days, and NEST had been a flurry of activity and some of the 'bots were always out hunting decepticons and nobody had ever had much of a chance to chat—but as it was a Saturday this time around, Mikaela wondered if maybe, things would be more leisurely.

It would be nice to get out of the city for once, at least, thought Mikaela. It felt like such a long time since she'd been on a good, long drive anywhere.

After towelling off, Mikaela threw on a short jean skirt, white blouse, and a splash of make-up. It was already so hot out that bringing a sweater along with her was unthinkable. She probably wouldn't be out too late, anyways—Bee hadn't exactly said what time they'd be back home by, but she'd never had a visit at NEST that had lasted longer than half a day or so yet. This was mainly to do with the fact that visiting hours only ran until sundown.

Bee arrived right at nine o'clock sharp, just like he'd said he would. When she'd heard the sound of the Camaro sweeping into the driveway she'd said a quick goodbye to Cal—who had the TV on in the living room and was watching the morning news—with a hug and a kiss, and mentioned that she probably wouldn't be back 'til much later in the evening because NEST was a good hour or more's drive away. She then knelt down to scratch Bonecrusher behind his ears in goodbye, wrinkling her nose as he tried to lick her face—his version of a very sloppy kiss.

" _No,_ Bonecrusher," she scolded him affectionately. " _Down_. I'll be back later, okay?"

He barked once, and Mikaela grabbed her purse, had a hard time closing the front door without letting Bonecrusher escape, and walked down to the driveway to meet Bee, where he was parked and waiting for her patiently.

She was thankful that he had the air conditioning running already because in the short time it had taken to get from her house and into the driver's seat, she'd begun sweating.

"God, it's so hot already," she gasped, closing the door before greeting the Camaro eagerly. "Good morning, Bee!"

"You excited?" he asked, revving his engine a little to express his own feelings of anticipation.

"Duh," she laughed. "It's not every day I get to go and hang out with you guys at _your_ place, you know!"

"Hahhahhah." Bee chuckled as he shifted into reverse and started backing out of the driveway. "We're not _that_ exciting…"

"Yeah, right! Well, compared to most of the people in this crumby city, you are. And that's _without_ the whole 'being aliens' thing."

"I told Optimus you're coming with me this morning," said Bee casually as they turned right onto Santa Rosa Place, which would end directly at the freeway ramp. It was the I-65 they'd want if they were to be heading north toward NEST headquarters, so Bee took them the back way past Mike's again. The shop was in full swing already, just an hour past opening—no doubt everyone wanted to get their bike repairs done before the heat of the day really picked up. She was glad that Mike had given her the option of having weekends off. "And actually… I asked him what he thought about ya practicin' driving with someone while we're there…"

Mikaela, who had been halfway through a yawn, choked. " _Seriously_?"

"Yeah. You're not mad, are you?"

" _Mad_? Bee, that's an awesome idea! I'm _thrilled_!" she grinned. "What did he say? Gosh Bee, you've been so helpful to me lately, I don't know how I'm going to repay you for all of this…"

"Forget about it, I still owe you, remember?" laughed the Camaro as he drove them over the overpass and around the clover-leaf that would take them onto the interstate, picking up speed all the while. "He said he was sure the guys wouldn't mind. Said it'd be really good actually, 'cause some of the guys tend to go a little nuts sometimes, never having any reason to get off base 'cept to go and hunt 'cons."

It was Mikaela's turn to laugh. "Yeah, I can see some of them being prone to cabin fever. Are you sure they wouldn't mind, though, Bee? I mean, I… I always feel kind of weirded out by the idea of actually _driving_ you guys, to be honest. You're not just _cars_ … you know? Sitting in the driver's seat when you guys are driving is one thing, and you remember how long it took me to believe you when you said you didn't care if I sat there…"

Bee laughed some more. "I remember. And being driven _is_ different from driving, but it's fine. It just takes some getting used to, 'n after a while it doesn't matter anymore."

"What do you mean?" she asked, confused. "What is it like, then?"

"Well, it's different for every 'bot…"

She'd never actually questioned the Camaro about it. She had her own ideas about what it would be like, but she was interested to hear what Bee had to say. "What about when Sam drove you?" she asked.

"Uh, well," said Bee, sounding awkward. "It was weird at first, but nice, after a while."

"Oh..."

Mikaela stared thoughtfully out of the window and was silent for a long time. They had merged onto the Interstate and were now heading north. They passed through dense industrial areas filled with warehouses, electrical substations, run-down bungalows, and auto wreckers, and eventually, these gave way to the city limit suburbs—which were large, fancy houses with sloping green lawns that were miraculously well-kept. The highway started to climb, and before long Mikaela found that they were on top of a harsh, high mesa.

The knowledge that Bee might have found being driven uncomfortable didn't really come as a great surprise to her. In her experience, it was hard sometimes, to be a passenger inside of an Autobot while sitting in the driver's seat. Your brain and body both wanted to take over automatically, and it took a lot of self-control sometimes to not just grab the wheel or step on the gas—something that she had always refrained from, having respect for the fact that the car was driving of its own accord and doing those things seemed like they would be a bit intrusive, even intimate.

It must be a similar awkwardness to that sensation of being useless, she thought, but in reverse—instead of feeling weird because of lack of control, it would be like _being_ controlled, like a puppet, almost—and you'd willingly have to submit to that unholy feeling of being powerless. This was why her and Sam didn't drive Bee unless they absolutely had to, and they were both internally pretty glad that such a situation had not happened, yet—not since the Mission City days, at least. It was just something they couldn't imagine being all that pleasant for the Autobot.

Thinking about it was starting to make her feel really nervous, though. Because, while the idea of driving Bee was already so uncomfortable, considering driving an Autobot she didn't even really know and subjecting him to such an experience was even worse, and made her feel nervous enough to wish she had not brought the subject up at all.

She retained her silence as they made their way through the plateau, its red, dead earth eventually becoming covered with a wide expanse of desert shrubs and cacti. Great valley rifts trailed here and there, forming gaping canyons which their highway snaked around with no protection from a sheer drop of some fifty feet, save for rather flimsy-looking aluminum guard rails.

It was Bee who finally broke the silence. "I didn't make you feel bad, when I said that stuff 'bout driving us earlier, did I?" he asked innocently.

Mikaela chewed her tongue thoughtfully. "Well, a little," she said. "Not a _lot_ , but… I don't know. I just keep thinking about what it's like when you drive me around as a passenger, and it's like you said—it's weird at first, but you get used to it. I just don't want to end up driving someone who doesn't like it, or something, is what I'm trying to say, I guess."

"It isn't that bad, Mickey. We get used to it a lot faster than you think, and after, it can feel kind of… good. Like… uhh," Bee paused, trying to think of a suitable metaphor, "Getting a back massage, or something. But like I said, ev'ryone's different. That's just how it feels for me."

Mikaela couldn't help but giggle a little. "If that's true, Bee… then I'm really surprised that you don't ask us to drive you more often…"

"Hah! Nah, it's cool. I like driving you guys around."

Knowing that it wouldn't be as awkward as she assumed it would be for her to drive an Autobot alleviated her stress a little bit, and she was able to fully enjoy the rest of the journey to NEST Headquarters without too many nerves. Still moving steadily north, they had descended from the high plateau into a country that was sparsely vegetated and somewhat mountainous; dried out creek beds followed the Interstate and high precipices dotted the horizon, culminating in rugged outcroppings of jagged, red rocks. It was a harsh place, and the wind drew steadily, blowing bits of loose, parched soil off of the barren rockfaces. Bee lamented that he'd only _just_ had a wash, before they rounded a corner and a great, much greener valley came into view.

The highway began to descend into this. A series of switchbacks brought them low enough to make out a glimmering river in its midst, with many small houses surrounding its banks. A faded, green sign with white lettering told her that they were entering the town of Eugene, population 3,000.

Eugene's main strip was quiet, dominated by a wooden, vintage saloon and a single hotel with an old-fashioned, street-level pub; Mikaela also spied a tiny barber shop, a craft store, and a thrift shop. They stopped outside of a 1950's-esque diner where Mikaela ordered a hamburger for take-out and used the bathroom.

While she was waiting for her food, she looked around the place, and found a handful of weathered faces staring back at her. Even the waitress had given her a once-over and whispered something in her co-worker's ear before she'd disappeared behind the bar to go and refill a trayfull of glasses. The other girl had snorted in reply and went back to taking orders.

It was not the most welcoming place she'd ever been to.

When she got back in the car, Bee had informed her that they were currently three-quarters of the way to base, and that they'd be arriving there within half an hour. Which was fine by her, she had to admit—while Bee's air conditioning was a godsend in this heat, it left her mouth sticky and dry in a way that even the bottle of water she'd bought from the diner couldn't fix.

The highway continued to follow the river until they reached a smaller junction and took a right onto a less-travelled expressway that ran straight back into the desert. The landscape became dead and boring again and Mikaela found her thoughts wandering back to the Autobots and NEST; which did nothing to calm her mounting nerves and excitement.

She started wondering which one of them would be the best one to help her practice driving. She would have felt most comfortable with Bee, of course, but Bee would have to change his vehicle mode from automatic transmission to standard, which she really didn't want to ask him to do. He was doing a lot for her already, and besides, he was probably going to be busy. He didn't get to be on base as much as the other Autobots, as he was essentially Sam's guardian; so it was likely that he was going to be hailed by the other 'bots and NEST officials with updates on worldwide goings-on.

No, it looked like Mikaela was going to be stuck in the company of another Autobot for the afternoon. She supposed Ratchet wouldn't be too bad of a teacher—she'd only met him a couple of times and had never had a one-on-one conversation with the medic before, but she got the impression that he was the calmest and most serious out of all of the Autobots, aside from Optimus Prime.

There was also Ironhide—but the weapons specialist could be a little bit abrasive sometimes, and she was not so sure that he'd make a good instructor because of it. She knew that he meant well and was trying to be funny a lot of the time, but Mikaela didn't always find having a giant cannon shoved in her face all that hilarious. Besides that, though, he was about as serious as Jazz had been—which was to say, not very serious at all and actually pretty funny. She felt like she could get along with him for sure.

With a pang she remembered the spirited Autobot that Optimus had introduced as his Lieutenant, Jazz. Jazz would not be there, as he had been killed during the battle of Mission City. Bee never talked about it, but even Mikaela could sense sometimes that it still affected him, and it made her feel really sad to know that her friend had lost someone so close to him in war.

But there had been four new 'bots on base the last time she'd visited a couple months ago. She had not had time to be formally introduced to them, but Bee had helped her out with their names—one of them, who had been hanging around with Ironhide most of the time, transformed into a sleek silver Stingray; Bee had said that his name was Sideswipe. There were also two 'bots who had been referred to on base by Ratchet and Ironhide as 'the twins', but Bee had said that _these_ 'bots were called Skids and Mudflap. The last of the four was a female 'bot after her own heart named Arcee—her alt mode was a motorcycle.

But Mikaela knew next to nothing about the four besides this information.

Last, but not least, was Optimus Prime, the leader of the Autobots. He would probably be the best trainer out of all of them, given his nature and experience. Endlessly valiant, calm, collected, logical, patient, and professional, and he had many years of knowledge of how best to command his fellow robots. Plus, his vehicle form was just plain amazing, and like she'd said to Bee the previous night, learning to drive truck was something she'd always thought about doing—but there was something about him that made her hesitate about asking him, even in the cool comfort of Bee's interior.

It was because his presence always drew out certain feelings in Mikaela more than any other Autobot; he always made her feel so small and self-conscious, for starters. She supposed it was his size, voice, and his complete seriousness that she found kind of intimidating at times. He was just so regal and powerful, and always in control. She couldn't imagine what spending a day off of base with him would be like.

But the idea made her wonder—who was the Autobot leader _really_? He couldn't _always_ be serious through and through, could he? When everyone was asleep, or between missions and only around maybe his closest friends, in situations where there were no more reasons to be endlessly brave and cool and distant with admirable self-control and professionalism, when he'd have an opportunity to really be himself—what was Optimus Prime _really_ like under that stoic exterior?

There was actually so much that interested Mikaela about the robot, and this was just the beginning—not that she'd ever admit it to anyone. Even just the small things, like his voice, had stuck with her. Not even Bee had a voice like that—it was just so deep, so powerful, it reverberated right into her very _soul_ sometimes when he spoke. Just the thought of it made the back of her neck prickle a bit.

Implausibly deep, inhumanly authoritive—and yet humanely compassionate and sensible. It was sensual, borderline kind of erotic—it was definitely not a voice that Mikaela was likely to forget any time soon.

It just made her even more curious.

"Hey, Bee," said Mikaela, spur-of-the-moment. "Can I ask you something?"

"Shoot," said Bee, speeding through a part of the state that was quite boring—the landscape had been largely unchanged for the past ten minutes, revealing nothing but a wide expanse of reddish brown wasteland dotted with shrubs.

"Your boss—Optimus… I was just wondering something about him."

"Yea?"

"Does he ever, like… you know… _relax_?"

Bee played a laugh-track loudly over the radio complete with clapping and cheers. " _Optimus Prime,_ relax? Oh, slag, no. Never. But we've always got a lot goin' on so maybe one day once the war's over, or something, he'll let go a little bit."

Mikaela whistled. "Damn. That must be hard on him."

"Probably. Hey—wait a sec. There was a time I saw Prime unwind, actually. _Wasted_ on high-grade. Only by mistake, of course. One night we were all drinking and I think it was Sideswipe who got the _awesome_ idea to switch the containers on him, and he'd been too tired to notice. Man, he was _pissed_ the next day, though… poor 'Sides thought he was in big trouble, but Prime just told him not to do that again."

Mikaela knew what high-grade was from Sam—apparently, there had been a time about a year ago when Bee had gotten in a spot of trouble from ingesting some of the stuff. The Autobots' personal brand of liquor, she could only imagine what it would be like to be in a room full of giant robots who were all drunk—including Optimus Prime.

"What was it like?" she whispered.

"Oh, you know. For all the differences between our worlds and species, we're not that different when we're blitzed," he chuckled over the radio. "And Prime is no exception. Why're you so interested in him all of a sudden, anyway?" he asked, and Mikaela could hear his suspicion over the radio.

"No reason," she said coolly. "I was just thinking about who'd be okay with letting me drive. Obviously I'd pick you, but I know you're gonna be super busy… and I thought, not Optimus, 'cause he's so busy all the time, with hunting decepticons and all. I wouldn't want to waste his time with something like this… but, maybe Ratchet could, he seems like he'd be a pretty good—"

"No way!" Bee said loudly, making her jump. "Prime'd be pleased if you asked and I know it. Like I said, he never takes a minute off…"

"I don't know," said Mikaela, trying not to let her face go red at the thought of actually asking _Optimus Prime_ to let her drive his—rather gorgeous—alternate form. "I—we'll see when we get there, okay? But I'm not promising anything."

"Whatever, suit yourself."

But Mikaela would be lying if she said that the idea of being trained by him was not… alluring, to say the least. She'd always had an admiration for his vehicle form, much like she'd had for Bee when they'd first met—only, with Bee, she'd been able to write off that attraction in the face of forming a respectable friendship instead, but… she barely knew Optimus Prime. She hadn't really had a chance to overcome her feelings—they weren't like, _out of control,_ or anything… and she was in a relationship… but she _was_ occasionally aware of just what kind of affect that big shiny chrome bumper and custom paint job could have on her.

A very sinful affect that she fully planned to never let anyone— _ever_ —know about. _Especially_ not him. God, no.

The last, somewhat shameful thought Mikaela had, before Bee had left the smooth asphalt of the Interstate behind and made a sharp right onto a half-hidden, overgrown and dusty dirt road seemingly leading into the middle of nowhere, was that the goddamned Peterbilt was fucking _sexy_ , and the Autobot it transformed into kind of was, too _._


	4. Choosing a Victim

**Redline**

.

 **Part 4**

It was a little ironic how the best-kept 'secrets' of the U.S. Military were often either common knowledge, or hidden in plain sight. For instance, Sector Seven and Area 51 were both 'classified' projects that had been semi-obvious to the ironically-oblivious public in some way; Area 51 having been made into the stuff of legends, and Sector Seven having been successfully hidden inside of the Hoover Dam itself.

It was almost laughable.

And, in true Military fashion, NEST was not well-hidden from the public eye, either; but instead its secrecy relied upon location, location, location. As it was usually a base that was accessed almost always from the air, there were only a handful of service roads in, and the one that Bee had chosen was not very well-marked or maintained. It was nothing but two twin tire tracks where the use of heavy Military vehicles had bushwhacked a wide path through the dry, desert scrubland, the only thing that gave away that the road had any destination at all besides your typical backcountry campground was a rusted, red gate about two minutes' drive down it.

The gate was open, but a large, filthy sign erected over one of its pillars read ' _DANGER AHEAD—PRIVATE PROPERTY, KEEP OUT_ '.

The main reason for such secrecy was, of course, the existence of the Autobots. It had been a semi-poorly kept secret thus far, to the displeasure of U.S. National Security—mostly due to leaked videos of the destruction their landing on Planet Earth had caused. There was only so much you could do when the World Wide Web has thousands of reposts of videos and photos of alien crash-landings a minute; except for try to contain the situation to the best of your ability.

And so, the location of the robots' newfound home seemed to have been kept successfully quiet through desolation and harsh security measures. Sam and Mikaela were both under oath not to mention anything that had to do with Sector Seven, NEST, or the battle of Mission City to any outsiders.

Mikaela and Bee had reached the facility after a twenty-five minutes' drive from Eugene, just as Bee had said they would. After about ten minutes of travel on a very dusty road covered with gravel that popped and crunched under the Camaro's tires, Mikaela caught a glimpse of the large Military outpost, visible from some ways down the trail due to its massive size. The tall guard towers and huge hangars loomed beyond a surrounding perimeter wall that stood out from the barren landscape of scrub and reddish brown dirt like some kind of ominous detention facility. Bee sped them toward this, with a trail of red dust following behind them, halting just in front of the imposing structure. Entering NEST was standard protocol for Bee, but the men leering from high up inside of the watchtowers still made Mikaela feel a little uneasy.

It was a feeling she always got whenever she visited headquarters, because as a civilian outsider, they were still wary of her and strict security protocols applied to her—even though certain people, like Cpt. Lennox, and of course Optimus Prime, thought she and Sam had as much of a right to be there as anybody did. It was very flattering, but Mikaela did not want anything more to do with the Autobot's war than she had already been involved with, if she could help it.

Military personnel greeted them just inside of the main gate. Bee had been cleared almost immediately, but Mikaela had to step outside of the vehicle for a quick once-over and energon sweep.

Once the guard had finished and she was allowed to get back into the car, she sighed with exasperation, smoothing the loose strands of hair that had fallen from her pony back over her head with an unconvincing word of thanks. Bee, however, couldn't contain his excitement about being back on base and wanted to show off—squealing his tires in a rather large burnout, he exclaimed over the radio, ' _Peace out, dawg_!' and sped off toward the airstrip.

Mikaela grinned and swatted at the dashboard while she watched the man who had cleared them in the rearview mirror. Through the cloud of tire smoke she saw him pull his radio out of his breast pocket and inform his superior that her and Bumblebee had arrived.

"You _bonkers_ Camaro," she snickered, wrinkling her nose. "Now it stinks like burned rubber. Thanks, dude."

"Anytime." She could have sworn the Autobot had winked at her.

NEST was super active, even for a Saturday. As they drove through the base in search of the Autobot's private hangar, Mikaela saw glimpses of some of the NEST higher-ups flitting in and out of several offices and supply buildings alike, as well as monitoring the usual array of training and shooting practice drills. She watched as lines of these soldiers marched in strategic formations, all decked out in the usual camo, each one holding up a rather large gun to their chest. Other groups of soldiers who were off-duty could be seen hanging around outside of the mess hall, or else sitting on shady benches and smoking; yet others still were crowded around parked rows and rows of all-wheel-drive military-issue vehicles currently being loaded with supplies.

The base's main airstrip was also a flurry of activity. Around ten planes were currently parked on the asphalt, their loading bays open while soldiers scurried up and down the access ramps.

Mikaela frowned. "Are you guys getting ready to go somewhere, Bee? There hasn't been decepticon activity or anything, has there?

"I dunno," the Camaro answered as they passed by the largest plane of all. Mikaela glanced into it just in time to make out an interior full of none other than three large four-wheel-drive jeeps parked and overladen with guns and ammunition. "Last I heard there haven't been any 'Cons 'round lately, but they could be doing something else—just 'cause NEST is where we live doesn't mean it isn't used for other things, too."

"Fair enough," she said thoughtfully.

The Autobot's Hangar was located on the other side of the gigantic piece of wasteland that made up NEST headquarters, and their private (rather large) section of airstrip was located directly adjacent to the main part of base. It was currently (and thankfully) devoid of both planes and soldiers—it seemed like the Military had finally given the 'bots a much-needed day off.

She felt her stomach flutter with nerves as she watched the enormous, semi-circular building approach. Clearly large enough for an Autobot to stand in, their home-away-from-home had a shiny tin roof that reached a good seventy or eighty feet at its peak, with a pair of huge double doors that made up the vehicular entrance; smaller, normal-sized doors were located here and there around the exterior of the building for human access. All doors had been shut tight against the blazing heat outside.

Bumblebee slowed to a halt in front of this, and Mikaela felt her sense of anticipation spike. She rolled down her window but regretted doing this immediately—the blast of heat she was hit with was worse than she was expecting and she choked, breathing thick fumes of hot tar and jet fuel.

"Oh my god," she coughed, her eyes watering against the temperatures. "It's _so_ hot out! I'm not getting out 'til we're inside."

The big double doors of the hangar ground noisily open, revealing shadowy depths that were invisible against the blinding brightness of the sun. She couldn't see a single thing until Bee had rolled all the way in.

Bee's second home always looked even larger inside, somehow. She supposed this had to do with how far the room actually extended—it was a deceivingly long, concrete-floored space that had been filled with several large television displays and computer monitors, all centered around a series of staircases and catwalks that allowed the NEST officials to speak with the Autobots face-to-face instead of having to look up at them all the time. Around this unit, the 'bots had clearly done their best to convert the roomy hangar into as much of a 'home' as they could—there was a defined communal space that resembled an automotive shop and several private 'parking stalls', all sectioned off with welding curtains to make stasis rooms. Mikaela counted one for each Autobot.

All of the 'bots looked around at Bee immediately as he rolled inside. Mikaela saw all of them freeze—Ratchet, who had cleared a space at his workstation for once, was engaged in a very intense game of something that looked like chess, battling a smaller robot that had to be Arcee with huge machine parts for chess pieces. The game had been so intense that Mikaela could tell at a glance that the Autobot medic was losing and was not too happy about it.

Ironhide and Sideswipe were lurking in the very back of the communal shop space, each relaxing on precarious-looking, welded-together stacks of hubcaps that were obviously meant to be chairs for the giant 'bots. They had been talking when they'd noticed Bee, but instantly they'd ditched the subject in favor of hailing the yellow-and-black 'bot as though he was a long-lost brother they had not seen in years.

And Optimus Prime was dead-center of the room, examining a very official-looking document and accompanying set of blueprints displayed on the largest of all the computer screens. He minimized the program quickly as Bee rolled into the hangar.

Being the Autobots' noble leader, he was the first to greet them. As he stepped away from the collection of screens and into the better, more well-lighted part of the room, Mikaela couldn't help but marvel at how shiny the giant 'bot's armour was—little white sparkles of fluorescent reflection flashed all over his body as he moved.

"Welcome back, Bumblebee." His voice was heavy with the weight of authority and leadership.

" _Bumblebee_!" cheered a slightly higher voice that belonged to Arcee.

"Yo, dawg," said Skids as Mudflap pushed him bodily out of the way.

" _Bee_! How ya been?"

" _What the hell_ , dude?" Sideswipe grinned down at the yellow-and-black vehicle. "What's goin' on?"

"Old squishy too busy to come along again then, hey?" came Ironhide's voice as the black robot pushed himself to the front of the crowd of Autobots to get a better look at his friend.

Bee released Mikaela's seatbelt and she knew that this was her cue to step out of the Camaro. She did so as gracefully as she could, readjusting her short skirt, and, ignoring how weird it felt to be standing in front of so many Autobots who she had not officially met before, she waved up at them and flashed them all a huge, glowing smile. "It's awesome to see you guys," said Mikaela before addressing Bee. "I bet it's good to be home again, isn't it, Bee? Man, he hardly shuts up about how much he misses you guys," she teased.

Being so accustomed to seeing Bumblebee transform, it did not phase her when suddenly, a robot materialized precisely where the Camaro had just been. "You're damn right," said Bee passionately over his radio.

"So what you been up to, Bee?" asked the robot Mikaela had previously identified as Mudflap.

"And what made you decide to tag along this time, squishy?" Ironhide teased her, grinning. "Long time, no see…"

"Yes. It is nice to see you here, miss Mikaela," said that unmistakeably resonating voice that always seemed to catch her attention at once, belonging to Optimus Prime.

Optimus never _really_ had to speak louder than any of them to make himself heard. Somehow, his voice had the capability of being carried to the very ends of the room and also straight into the very center of Mikaela's chest, buzzing with each syllable. She felt her heart twinge as the other bots fell silent at once, and she found her eyes immediately snapping up to look straight into the Autobot leader's.

The large screen behind him glowed almost as brightly as these eyes, but not quite—his optics were electric-blue and the most visually-drawing things in the room, in her opinion. Looking into them had always made her feel strange, somehow—it had been the same ever since the first time they'd met. Their sheer brightness and intensity was unholy and otherworldly made her almost believe that he was staring right into her very _soul_.

Mikaela blinked. "N-nice to see you too, Optimus. It's been a while," she said, trying to ignore the way her voice sounded ridiculously high-pitched compared to his deep, resonating one.

Optimus knelt down on one knee, lowering himself to her level to talk while the other bots hung back out of respect for their leader. The closeness made the hairs on the back of her neck prickle, and she found herself trying her best not to let her face go red.

"It has. I hope all is well between you and Sam?"

Mikaela cleared her throat and was happy to hear her voice sounded a little deeper, this time. "Uh, yeah, we're okay," she lied. "Sam's just away for the weekend with his family."

Standing in front of the Autobot leader in her short skirt, being subjected nonstop to his penetrating gaze was making her feel self-conscious and naked even more nervous than she already had been. She hadn't expected him to ask about her and Sam's relationship, and, truth be told, even if she'd known Optimus Prime better, she would still probably have had a hard time explaining to him how her relationship with Sam was currently going. Being here, in front of him, was enough to make the words stick in the back of her throat—which was not something that usually happened to Mikaela.

Mikaela was outgoing—not always, but when she felt like it. She usually didn't like talking to people who tried too hard to get her attention, or people who tried too little to get it—this was mostly because, to the outside world, she was very beautiful, and people had a habit of treating her differently because of it. Truth be told, she just wasn't that into always having to deal with it—she just didn't _care_ that much, but what she _wasn't_ used to was other people _not_ caring. This was another reason why the Autobot leader threw her off. It was like, this kind of curveball, and she found herself drawn to him because of it—like she had asked Bumblebee earlier, she wondered what it would take to shatter the Autobot's stoic exterior.

She didn't have a crush on him, or anything, though. She was just curious about him.

But she could not stop _looking_ at him right now and it was freaking her out. His mere presence and appearance implied his incredible importance as their leader, and it was both fascinating and intimidating. It was in the way he composed himself, taller than all the rest, towering over her even while down on one knee, seemingly radiating sheer power and authority—it made her feel so tiny. He was not like Bee—Bee always had an air of silliness about him, no matter what he was doing. It made the smaller 'bot more relatable somehow, made him easy to be around to the point where she could sometimes even forget that he was a giant alien robot—he was more _human_.

Optimus Prime, though? He carried with him the knowledge of the incomprehensible amount of years he had been alive for, all of the good and the bad things he had lived through, and the weight of the current phase of their war. He felt old, and sturdy, and so much more than human.

"That's good to hear," said Optimus. If he knew that Mikaela had lied, he didn't say anything. "I think it's your birthday next weekend, isn't it?"

"Yes, Sir," Mikaela replied, thankful that he brought up a subject that she could elaborate on. She felt a little foolish, conversing with someone as old and learned as Optimus Prime without anything interesting to add, so she decided that it was the perfect time to bring up part of the reason Bee had offered to take her along on his trip to NEST. "Yeah, um, about that. Bee had a really good idea about something, and I—I was wondering, if…"

She swallowed hard. Even though she knew that Bumblebee had probably already told most of the bots at least part of the story when he'd asked if he could bring her along, Mikaela was a pretty private person, and no matter how much or how little he had said to them about Sam and her, it did not make her any more eager to discuss her personal life with these robots. She was comfortable with Bee, and—not that the Autobots weren't a friendly bunch—she just didn't _know_ them like she knew him.

She knew she had to tell the truth regardless, though. It didn't feel right to ask for their help unless they knew everything.

Or, almost everything.

Mikaela closed her eyes and exhaled deeply. "Um, actually, Optimus… Sam and I haven't been doing too good."

A ripple went through the crowd of robots. Mikaela noticed a few raised eyebrows and many of them shared a sidelong glance with each other. Sideswipe whistled.

"Damn," he said. "Lucky they haven't bonded yet."

Something about this apparently bothered Optimus, for he turned to Sideswipe with a scowl and said, "Things are different here, remember, Sideswipe. Humans are not Cybertronian… to fall out of love when so young, as sad as the concept may be, is not always pitfall for their species—but rather, for some, a necessary element of human development."

"Um," said Mikaela, somewhat confused. "Thanks… I think?"

Optimus chuckled. "You have nothing to worry about, young human."

She looked in turn at each of the other robots in the room. "We didn't mean for it to happen," she tried to explain. "It's just, we've got a lot going on in our lives, you know? I'm always working, and Sam is going to be going to college. We're kinda going in completely separate directions… but we're not giving up yet. Bee's been helping us work through it a bit—he's a great bot to have around, guys. I'm really lucky to have him as a friend."

Mikaela looked affectionately at Bumblebee and patted him on the highest point of him she could reach—his mid-shin. Bee made a mechanical sort of whine noise in reply that sounded most like a robot equivalent of 'awwwe'. "You're gonna make me blush," he replayed.

"Really, Bee," she continued with a meaningful look at the yellow-and-black 'bot, "Thanks. And as for Sam and I," she turned back to Optimus, "Well, I have this idea of how to fix things. But, uh, I kind of—accidentally—found out what he's getting me for my birthday—he's got me this _super sweet_ ride, oh my god. And he wants us to take a nice trip in it, all by ourselves… go spend a couple of nights in Las Vegas!"

"That sounds great, Mikaela!"

"It does, God. But there's a problem. I was saying to Bee, it's been _years_ since I've driven anything standard. I'm… a little out of practice, to say the least. And as Bee probably mentioned to you guys, I could use a little extra help with that… it's partly why he's brought me along, he said. He'd help if he could, but the Camaro's an automatic and he's probably going to be pretty busy around here, right? His one day to visit, and all…"

"He mentioned that," said Ironhide, looking sideways at Bee before asking Mikaela a question. "But I was thinking— you work in a shop, and you're a human med—mechanic, aren't you? Couldn't you just convert the thing to automatic yourself?" he asked.

Ratchet answered the question for her. "Earth machines are not like us, Ironhide, remember. Humans cannot simply switch their internal mechanisms at will. It takes a considerable amount of time, mechanical aptitude, and expertise for a human—or as you may call them, squishies—to be able to complete the process. Which I don't doubt miss Mikaela has," he nodded to her respectfully, "but I hardly doubt that she could complete such a task by next weekend on her own."

"Right," said Mikaela, "Well, I'm not _that_ great of a mechanic, and I also don't exactly own the car. It's a rental. And Sam's not supposed to know that I know about all of this."

"…Oh. You guys _do_ that?" Sideswipe asked, looking kind of offended at what she had just said. "Rent out _cars_? For anyone to smear their greasy little hands all over—ruin their paint jobs?"

"Was this the same surprise that Sam had asked you to advise him on last weekend, Bumblebee?" asked Optimus sternly, and her eyes snapped back to the Autobot leader's. God, she wished that she could look somewhere _other_ than straight into his eyes whenever he spoke—the prickling feeling of over-awareness only increased each time and, again, she willed her face not to turn pink.

It was lucky it was somewhat dark inside of the Autobot's hangar…

"Yeah," said Bee. "I, uh, might've been the one to tell her." The poor yellow 'bot looked down at his feet.

"You did not tell us that part..."

"Please, um—Optimus—" interrupted Mikaela, worried that Bee was going to be in trouble. "It wasn't really his fault, though. Actually, things probably would've gone a lot worse if he hadn't told me. We'd been really distant, sometimes arguing and stuff, and… now I think I understand. And without Bee here I would be pretty mortified if next Saturday came and Sam handed me this drop-dead _gorgeous_ machine and I had to sit there and pretend to know what I was doing and knew how to drive stick or whatever and I crashed it and he'd never get his deposit back, or something. I mean, I'm a great driver—I'm just out of practice, and—"

Optimus held up a gigantic hand to silence her. "It's quite all right, Mikaela." His voice was so calming she immediately felt her defensiveness melt away. "I understand—and that is why I have agreed with Bumblebee, that one of us must be appointed to instruct you on how to, as you put the term—" and either she was crazy, or something like a hint of a smile flashed across the Autobot leader's face, "—drive stick."

It was probably the most awkward way he could have put it. Mikaela flushed, unsure as to if the Autobot leader knew how much of a human innuendo the phrase was when put like that or not—it was probably innocent—but even if he didn't, the other bots probably did have some inkling because the room was suddenly ringing with the sound of several of the robots' hearty laughter and a resounding _crash_ as Ironhide threw himself bodily to the ground, pounding the concrete floor with his fists.

" _Drive stick_ ," he croaked when he'd finally finished, "Drive _stick._ Oh, boy, Optimus, I never thought—Primus, you shouldn't talk that way about a _squishy_ —"

Sideswipe, too, had tears of mirth—or rather, oil?—coming from his eyes. When he was done, he whistled. "Damn, Chief," he choked. "I didn't know you like 'em raw."

"Autobots, control yourselves." Optimus looked annoyed. "That is not what I meant, and you are aware of it. Human linguistics dictate that the use of slang is appropriate in casual environments. I only wished to make miss Mikaela feel a little more at home, by—"

"Yeah, right," choked Sideswipe.

Optimus ignored him. "Mikaela," he said in a forcefully level voice, "Bumblebee had also said that it was your wish to learn to drive a truck someday."

 _Oh, God—_ had her face already been red? Because now it was scarlet—Mikaela turned to Bee and swatted him against the ankle again. " _Jesus,_ Bee, you really do have a big mouth, don't you?" she tried to laugh, but Optimus was still staring at her with those optics, and it felt like the bottom had just dropped out of her stomach at the idea of going for a drive with Optimus Prime…

"Is this still accurate? Because if it is, I would be more than happy to—"

But Mudflap, Skids, Sideswipe and Ironhide could not resist. Mudflap and Skids were on the floor laughing and Sideswipe wolf-whistled. "Sounds like _the boss_ wants you all to himself," he snickered. "I get dibs on you for next time, kay?"

"Damn, squishy," Ironhide winked at her.

"Silence!" Optimus had barely raised his voice, but the coldness of his tone made the room instantly drop a few degrees. "This attitude _exactly_ is why I wish most to be the one to instruct her," he growled. "I don't think Sam— _or_ Bumblebee, for that matter—would think very highly of me if I let her be taught by a bunch of fools who could not take matters seriously! Autobots, Mikaela asked for our help, and it is our _duty_ —as friends of Sam's—to provide her with that help in a respectful manner."

"Aw, slag. We do respect her."

"Yeah, we were just playin', Prime."

"I am aware," Optimus continued as though he had not heard them, "That most of you in this room are certainly lacking in self-control and the ability to act serious. So, unless miss Mikaela objects—and you of course will have the final say—" he nodded to her, "—I would prefer it if I were to be the one to teach you."

Everybody in the room looked at her. "I—uh," she coughed, feeling put on the spot. _Holy shit._ "Wow. Um… sure, Optimus, that's…"

The unfinished sentence hung awkwardly in the air.

"Are you positive that you would not be more comfortable with another Autobot?" he asked again, sensing her discomfort. "Though I can guarantee that I am able to act more _professionally_ than some." he glanced at Ironhide and Sideswipe, who were currently looking anywhere except at Optimus. "I am also aware that my vehicular form can be… somewhat daunting."

She could have _sworn_ there was a smile in his voice this time, but his face remained passive and none of the other 'bots had thought what he'd said was funny, so she assumed she must have imagined it again.

But _Optimus Prime…_ wanted to be the one to help her practice driving _—_! Was she sure that she could handle herself behind the wheel of a big rig? It had become such a distant dream of hers that she couldn't fully believe that it was a thing he was actually offering. Her own little motorbike seemed just about as big and powerful as a tiny little bug compared to the Autobot leader's magnificent alt-form.

She had set out with Bee that morning with the distant hope that she'd get a little practice on a standard, if she could find a suitable 'bot who'd agree. But a _truck_ … well, there was no real argument against it that she could come up with. It _was_ experience on a manual transmission—she knew enough about it to know that the concept for a truck was basically the same as a car at its core, and that if she could drive a big rig, she should be able to handle that little Camaro no problem.

There was really no downside—not any that she could currently come up with, at least.

A few of the bots, however, seemed to be getting over their fear of arousing Optimus's frustration, and were starting to voice their opinions again—Sideswipe and Ironhide in particular. It looked like they were both still very keen on having her practice with them, too.

"You sure you don't want to pick me—oof," started the Stingray before Ironhide elbowed him in the middle.

"You think she'd pick _you_ over _me_? You haven't got cannons like these." His arm transformed into a truly massive cannon, which he flexed and blew smoke from the end of, showing off. "I'll keep you safe, squishy. You won't have to worry about any 'Con's around when I'm with you."

"In your dreams," Sideswipe shot back. "You gotta have more than just muscle to show 'em 'Cons who's boss."

"Yea? And you think _you_ got the brains to beat _these_ cannons?"

"Even if I don't, I definitely got the skills, I'd smoke you on the road and you know it—"

But this, apparently, was too much for Ironhide, and the room was suddenly filled with the loud clashing of him transforming into the enormous black Topkick. "BRING IT ON!" he roared at Sideswipe over the revving of his engine. "I'll take you on right now, just watch me!"

" _Autobots_!" This time, Optimus really did raise his voice, and Mikaela felt goosebumps erupt on her arms that had nothing to do with the ambient temperature. "Enough."

Mikaela immediately got the impression that Optimus was probably the only force in the entire universe that could make either Autobot back down from such an invitation, even if only for the moment. The room was filled with renewed silence as both robots glared challengingly at each other. "Tonight, on the tarmac," finished Ironhide.

"You're on," answered Sideswipe.

"Mikaela?" said Optimus quietly, and Mikaela jumped, having been so distracted by the bickering robots that she had almost forgotten that Optimus had asked her a question. "Have you made a decision?"

"Uhh…" she started, staring up at the Autobot leader. She still had not come fully to a decision that felt like the right one, but she was also very aware that there was no real downside to her accepting Optimus's offer. In fact, if she didn't, she knew that she'd just end up mad at herself for being chicken. _He's only a truck…_ she thought to herself. Why should she be so freaked out about the idea of driving a goddamned truck, even if the truck happened to be a rather attractive sentient robot?

 _Fuck it._

"Hell yeah," Mikaela answered strongly, sparing only a second to think, ' _Good God, what am I getting herself into?_ ' before continuing, "I've decided, Optimus, it sounds awesome. Seriously. Bee got it totally right—" she flashed a sassy smile as she looked up at the enormous robot towering over her and winked. "—I've always wanted to drive a big truck."

She had to giggle a little bit to herself as the rest of the bots whistled and whooped in appreciation and even Optimus himself looked a little embarrassed at what she'd just said.

" _Damn_!"

"High-five, squishy! Nice one!"

But it had all been in good fun. She wiggled her eyebrows and winked at Sideswipe and Ironhide, which made Optimus give a deep, resonating chuckle.

It wasn't every day that she got to give an intergalactic war hero some cheek, after all.


	5. More Than Just a Truck

**Redline**

.

 **Part 5**

Bumblebee, Sideswipe, and Ironhide had escorted Mikaela out onto the airstrip. The midday sun beat down ruthlessly, and she found herself thinking longingly of air-conditioning—she hoped that Optimus would have the Peterbilt's interior nice and cool for her when he was ready. He had just a few things to wrap up before he'd be able to leave base with her, though—Mikaela and the other Autobots hung around just outside the hangar while waiting for him to inform Military officials as to where he was going with Mikaela and why.

Bee was standing next to her, his shadow towering over her, providing a little relief from the scorching sun. Just as she had guessed, Bee would be busy spending the entire time she was gone with Captain Lennox and his Military crew. Ratchet and Ironhide volunteered to debrief Bumblebee on current Decepticon events in Optimus's stead.

Mikaela had thought that there shouldn't have been much to fill the young Autobot in on, as the last time he'd been on base was just last week—however, she had caught enough of the conversation to deduce that NEST had received a new lead on a brand new Decepticon hideout and plans for a raid were already in preparation. Just the thought of the 'bots going into battle again so soon made her stomach feel full of knots—was it just her imagination, or was it becoming more and more frequent that Sam's garage was left empty for days at a time as Bumblebee joined the Autobots to take out stray Decepticons all over the world?

"You're not going to be busy for long are you, Bee?" she asked, squinting up at him against the brightness of the sun.

"Dunno," he said, shrugging. "Lots to talk about…"

"Ah," said Mikaela sadly, noticing that the Camaro looked a little bit put-out at the idea of preparing to go into battle again so soon. "But you'll be okay without us there, right?" she tried her best to flash him her most uplifting smile, squeezing part of his ankle affectionately.

"Don't worry 'bout me." Bumblebee kneeled down to her level, fixing her with the kind of look he usually reserved for Sam—almost like a sad puppy pining for his owner to scratch his head. "Go have some fun, kay?"

"Yeah," said Sideswipe from behind as he patted Bee hard on the shoulder—the resounding crash made Mikaela jump. "Us Autobots can take care of ourselves… And we've never met a 'Con that was a match for our little Bumblebee!"

Mikaela tried to laugh, but she still felt uneasy. "I'll try, Bee."

"You nervous?" Bee asked.

"No way!"

But apparently she hadn't been that convincing.

"I don't believe it," gasped Ironhide mockingly. "Our little squishy is _scared_ of the big boss!"

Mikaela scoffed. "So not. In your dreams, Ironhide… I can take on Optimus Prime, anytime…"

"Oh yeah? I'll tell him you said that…"

"You wouldn't!"

"Relax," he winked. "I'm just teasin'. And Prime's a good guy. He won't bite… that is, unless you happen to come across a stray decepticon while you're out… then you'd better start running for cover."

The 'bot was chuckling evilly to himself at the joke, but Mikaela didn't find it that funny.

"That's not likely to happen, is it?" she asked, her voice pitched a little higher than she'd meant it to be, worried that the Autobot leader could somehow act as a magnet to any possible decepticons within NEST's vicinity before she remembered that the Autobots had ways around that. She still couldn't wrap her head around how they could detect decepticons so easily and yet keep themselves hidden, however—some kind of cloaking signal, she guessed.

"Of course not, Mickey. 'Hide's just pullin' your leg," Bee reassured her.

"Yeah," supplied Sideswipe. "Prime wouldn't take you out anywhere he didn't know was safe. The 'Cons got all sorts of little hidey-holes all over the place but we know our own backyard. And they're not too smart… nowhere near as smart as Prime."

"Okay, good," she sighed, looking thankfully at Sideswipe and Bumblebee before she turned and gave the weapons specialist a disapproving look, slapping him playfully across the knee. "You had me going there for a 'sec, Ironhide. But are you sure you guys are going to be okay on base without us? I mean… has Optimus even _left_ the base without you guys before? Or—"

"You worry too much, squishy," Ironhide laughed.

"Yeah, Prime has his own way of calling us if he needs us. We'll be fine."

She knew that Sideswipe meant the radio-esque private comm-link that the robots shared to communicate with each other over long distances. And she was sure that her and Optimus weren't likely to travel far enough away from base for them to be out of range—no, she was not worried about keeping in contact.

Not exactly.

Her fears stemmed from the guilt she felt from stealing the Autobot leader away from base in the midst of what was apparently such an important time—maybe it would have been better to request someone else to accompany her, after all—

But before she could change her mind or voice her thoughts aloud, she was cut short by the sight of Optimus rolling forward out of the shade of the hangar. He was already in vehicle form, and through the distortion of heat waves radiating from the superheated asphalt, the red-and-blue custom flames across his front appeared to flicker like real, live ones. The Peterbilt's huge size and the blinding reflection of all of the shiny, chrome accents drew every eye on the tarmac as he approached—Mikaela wondered dimly if maybe the truck wasn't visible even from the goddamned _moon_ with shine like that.

It took her a couple of seconds to realize just how intensely she'd been staring, but there was just something so magnificent and regal about the great big Peterbilt—much like how Optimus's presence in bot-form made her feel so fragile and small. And like the other 'bots on base, Mikaela had not spent enough time around Optimus to have a real chance to study his appearance beyond just admiring the overall effect (which was pretty damned nice, she admitted)—meaning that she had not had the opportunity to admire his truck-form much either, but now that she _did_ have that opportunity…

She had to say…

Optimus Prime had to be one of the most _gorgeous_ vehicles she'd ever laid eyes on. The custom paint job was a mix of her two favorite colors and looked freshly washed and waxed; every inch of chrome was polished and gleaming; his Michelin tires were velvety black with treads so thick they had to be brand-new; and his enormous smokestacks towered over her head. His rather large chrome front bumper was so low to the asphalt that Mikaela had to wonder exactly how the huge truck managed to skirt his way around obstacles he found in his path—but then again, he _was_ an Autobot.

She could hear his engine idling through the truck's pristine front grill. It was a low rumble, more like a quiet growl than anything else, and it made her think back to that '65 cherry red Camaro she'd loved so much as a child—that big-block engine being the only thing she could remember sounding so good. But there was just so much more power in Optimus's idle, so much life, so much… _expression_ —just like in the 'bot's true form, the Peterbilt's 'breath' was not just a steady cyclic vibration, but was something that varied much in pitch and speed with oscillations that cycled the internal rhythms of his spark.

The truck was—simply put—alive.

And she was going to spend an _entire_ afternoon out with this, with _him_ , with nothing for company but him—Optimus Prime. It was finally starting to sink in. She felt her heart beat faster inside of her chest— _she was really going to drive him…_

And that thought was so enticing, Mikaela grinned in spite of herself as Optimus stopped directly in front of her. The long nose of the Peterbilt dipped a little with the hiss of his air brakes engaging and the deep vibrations inside of her chest halted as he killed the engine.

For one split second, a flash of remorse passed through Mikaela. Here she was, on the very first Saturday in a long time that she had been apart from Sam for, feeling _this_ excited about going out alone with Sam's best friend's commander.

But he was kind of fucking hot, and it was turning her on, if she was honest. And—he'd _wanted_ her to drive…

She pushed the thought aside. Optimus had said outright that he had wanted to be the one to take her out because he respected Sam—it had been out of respect, and yet here she was, practically drooling over him.

It wasn't right.

 _It's not like that_ , she told herself. _It's different. I just think the truck is hot. That's it… right? It_ is _a sweet ride. But he's not a truck, he's an_ Autobot _… the Autobot's_ leader… _Sam's_ friend… _what the hell, self…_

No. She was just excited to be going for a drive, and that was all there was to it.

And besides—if there was anyone on this planet that would be more respectful and professional about the situation than Optimus Prime, then she'd be very hard pressed to find them.

"Are you ready, Mikaela?" asked Optimus, his voice oozing from underneath the Peterbilt's hood.

Mikaela swallowed and then flashed a teasing smile at the windscreen, trying to make herself seem less nervous than she felt. "I think so... ready as I'll ever be to drive a big semi, anyways."

The driver's side door swung open of its own accord, an invitation for Mikaela to climb up into the cab. She walked around to the side of the truck and, before she could change her mind, reached out and grabbed the shiny handrail.

"See you when you get back," Sideswipe said from behind her.

"Yeah, see you squishy. Make sure you keep Prime in line…"

Optimus chuckled at this, and the first thing Mikaela noticed as she straightened her skirt and sat down on the cushy, air-ride seat was that she didn't just _hear_ him laugh—the entire vehicle had moved with it a near imperceptible amount. He'd rocked a bit on his own, too—almost like someone readjusting themselves into a more comfortable position. Was he not used to having a human passenger inside of his cab?

"Will do," said Mikaela, answering Ironhide as she groped around for the seatbelt. "And try not to have too much fun without me, okay, Bee? You guys stay outta trouble while we're gone," she teased.

She felt Optimus nudge her hand with the seatbelt and she pulled it over her shoulder before turning in her seat to glance around at the 'bots. Bee looked as innocent and cheerful as ever, but there was an almost knowing smile on Ironhide's face.

"We will if you do…" he winked.

"Bye, Mickey!"

And then, before Mikaela had a chance to really think about the connotations of what Ironhide had just said (having suddenly remembered that Autobots could read human pheromones, and that hers were probably telling all of them a mix of things she'd really prefer none of them to know, like that it had been what genuinely felt like an achingly long time since she'd last had sex, and that she was currently finding the Autobot leader's vehicle form more… entrancing… than ever), Optimus had closed the driver's door and the cab was suddenly plunged into total silence.

 _We will if you do…_

She just hoped that the Autobot leader had way too many important things currently on his mind to notice the heady mix of pheromones that the human woman currently seated inside of his cab was emitting…


	6. Chrome, Steel, & Sex Appeal

**Redline**

.

 **Part 6**

The quietness of the Peterbilt's interior was broken only by the steady hum of the air conditioning. Unbelievably welcome cool air blew from vents on the dash and onto her flushed, sweaty face, providing some relief from how hot it had been out on the asphalt.

"Oh, thank god, Optimus," she sighed, tucking the loose strands of hair that fell from her pony behind one ear. "It was _boiling_ out there."

Optimus answered via the cobalt-blue LED radio console which flickered in time with his words. "I have set the cab temperature for seventy degrees Fahrenheit," he said, his deep, resonating voice sounding even more pronounced over the stereo. "Which I think is optimal for your species—but let me know if you begin to feel too cold, Mikaela."

Mikaela smiled warmly at the radio. "Will do, boss. But I don't think you're going to have to worry. It's _so_ much nicer in here."

The sweat on her forehead began to dry and she settled into the seat, finally starting to relax with a sigh. Even some of her nerves were beginning to subside, helped along by how comfy the cab was—the driver's seat was made out of some kind of squishy leather, soft enough for her to sink right down into as she adjusted to the cab's cooler temperature.

There was nothing worse than waiting for things to start happening and overthinking them while you wait—her imagination had a habit of going into overdrive—so she always felt better when it came time to actually _doing_ things for this reason.

Mikaela's hands found the steering wheel. Much larger than a car's, it was blood-red and ribbed all the way around for extra grip, its exterior coated with a layer of smooth rubber that was pleasant to the touch. Three chrome spokes met at a horn that was engraved with the Autobot symbol which she traced with a finger, admiring its soft aqua glow.

"Jesus, Optimus," she muttered. "If you weren't actually an Autobot, I'd have to say that you're one _hell_ of an expensive truck…"

The Autobot leader liked this. "Am I?" he chuckled. "Maybe. Transportation of goods is an important service on your planet, after all… but, as you already mentioned, there is the slight problem that I occasionally transform into an Autobot. I doubt any of your race would particularly enjoy that small technicality."

"Sure they would," shrugged Mikaela. "Who _wouldn't_ want to drive a truck that could transform into a giant robot?"

"That is…" Optimus paused, "I think the term you would use is 'flattering'. But certainly those sentiments would begin to change with time."

"I doubt it. I still like driving around with Bee whenever I can. You guys can be really great company…" she smiled as her eyes wandered over the glittering dashboard. An impressive, somewhat daunting display of white-lighted and chrome-rimmed glass gauges, dials, switches, and buttons that looked immensely complicated winked up at her.

She whistled. "Dang, Optimus… you know, the only machine I've ever seen that looks as complicated as you do is a cockpit…"

She felt the entire vehicle sway a little as he laughed. "Heh heh heh. Don't be alarmed, Mikaela—only a few of these gauges will matter. Several of them have nothing to do with driving at all—some display vitals that are not specific to my vehicle form, and others are for instruments I have in place for things such as tracking possible energon signatures and concealing my own, and emergency communications."

"Okay, good," she sighed with relief. "'Cause you _might_ just look a little overwhelming," she grinned. "Not saying you _do_ , but…"

"Never forget that I agreed to do this under the premise that you will of course need my help. There is no shame in that."

The tone of his voice was so reassuring that she felt all of her worries melting away automatically. Its depth was almost magnified by the slow flickering of the cobalt-blue radio display which complimented the polished, deep cherry-stained dash beautifully, its soft phosphorescent glow very visible due to how much light the Peterbilt's tinted windows kept out and how low his big chrome visor hung over the windscreen.

"Thanks, Optimus."

"It is no problem whatsoever."

Mikaela continued to look around, taking in the rest of the Peterbilt's cab. The contrast in lighting between the blinding sun reflecting off the asphalt outside and the lazy, reddish residual glow coming from the dash and the burgundy interior upholstery that matched it gave the truck a somewhat intense feeling of being a rather private space. The emptiness behind the cushy driver's and passenger's seats that led to the comfy-looking sleeper at the back did not help, nor did the tufted, leather roof above her head lined with buttons that was just as dark as the cherry red dash was—it made the entire cab feel like she was sitting inside of somebody's bedroom loft.

It was a semi-workable metaphor, she thought, as the entirety of the cab really _was_ an actual part of the Autobot himself. The realization made her feel a little guilty—was she invading his personal space?

And the scent, she noticed suddenly, did not help make it feel any less personal.

It reminded her of times she'd walked into ex boyfriends' bedrooms that were like this, rooms that were small and cramped but clean and tidy that always smelled _good_ that had belonged to boys who'd spend hours on the track, or hours a day lifting weights. Boys who were not like Sam and did not leave their dirty socks everywhere, boys who showered a lot and how they'd still smell afterward of something Mikaela couldn't quite place but oh _heavens_ it was amazing. It was the smell you'd find on their hair and skin and that would cling to you long after you'd left, one that could persist through her own showers and sprays of body mist—it was a scent that seemed to bind to the very olfactory sensors inside of her nose.

It was—quite simply—the strong smell of attraction.

And Mikaela used to think that maybe it was a certain type of cologne, or maybe the scent from burning candles or incense that produced such an intriguing aroma—but that was before she'd found herself seated in Optimus Prime's Peterbilt form and surrounded by the thick, heavy (but not overpoweringly so) musk of the truck's interior. Because there was for sure no incense, nor cologne, nor candles in here—the smell was coming from _him._ Much like how the Autobots could smell _her_ pheromones, she was picking up on his _—_ it was the result of being physically closer to Optimus than she'd ever been before.

And now that she'd noticed it, it was driving her absolutely _crazy._ What it was most like was a mix of the somewhat rustic scent of quality, brand new leather upholstery, the tantalizing perfume of fancy shampoo, and the distinctive mechanical odour of expensive machine grease. The grand effect was heavy with masculinity and unexpected sex appeal and it was a definite turn-on—how could a truck smell so _good_?

It was nothing like Bee's scent, although the Camaro didn't smell _bad_ or anything—for some reason, Mikaela just wasn't as— _receptive_ —to the young Autobot as she was to the Peterbilt. He smelled good, too, but she didn't think she could describe it as being anything markedly past the average new-car-smell that went along with a more modern vehicle. Perhaps, there had been an underlying spritz of pine that she'd assumed had come from the air freshener he always kept in the center console, but that was about it for Bumblebee.

Optimus, though—this was going to stick to her long after she'd left the truck's cab. She was going to smell him for _days,_ and she knew it—and the worst part of it was that the scent was just so damned undeniably _attractive._

Shit _._

Clearing her throat, Mikaela peered through the front windscreen, seeking a distraction. She could see the top of Optimus's long, flat hood, beyond which she had a pretty great view of the horizon. It was pretty impressive, actually—she was aware that truck drivers had great visibility over the tops of smaller vehicles due to their height, but actually _sitting_ inside of a truck put a new perspective on it and gave her a newfound appreciation for just how big the Peterbilt actually was.

It was _enormous_ , and it was _so_ hot that it made her shiver a little.

Something that Optimus noticed immediately.

"Are you cold, Mikaela?" he asked, sounding concerned. "I can raise the temperature if you are uncomfortable, remember."

"I—I'm fine, Optimus," she said unconvincingly.

"Are you certain?"

He sounded so anxious that it melted her heart a little. "Honest, Optimus," she sighed. "I'll tell you if I'm cold. I promise, okay?"

"Okay. Are you almost ready to begin, then?"

"Oh, right—yes, almost—"

She had almost forgotten that she was supposed to be _driving_ the truck, and not just marvelling at it. Mikaela begun to feel the front of the seats for the adjustments that would bring it closer toward the pedals, her knuckles brushing against the cool glass of the Peterbilt's mirrored floor as she searched. When she found it she pulled and slid the chair a couple of inches forwards, reaching out with her foot to test the positioning. She tapped each pedal once and, satisfied, she straightened, rolled down her window (wrinkling her nose as a wave of heat that hit her in the face as she did so), and began to adjust the side mirror.

She was privately very thankful that he had no trailer on the back, but as she reached up the readjust the rearview she noticed that Optimus didn't even have a window on the exterior of the cab—the mirror had no real function except to give her a pretty good view of the sleeper. It would make driving using the side mirrors that much more important, and she wondered to herself how on earth the Autobot could see without a window on the back.

"Hey, Optimus," she said before she could stop herself. "Can I ask you something?"

"Go ahead, Mikaela."

"Kay, this is probably gonna sound weird, but," she wondered how best to phrase what was on her mind, "But when you're driving around, like when you're in this form… when you're the Peterbilt—can you actually _see_ out of the mirrors, like are your eyes—?"

"They are not photoreceptive, if that is what you are asking," said Optimus calmly.

"So how the hell do you see, then?"

"…The windscreen is semi-photoreceptive," he answered.

"But that's only straight ahead," she said. "So you can't see me sitting back here?" she waved at the windscreen. "Or behind you while you're driving?"

"Not in the… _typical_ sense of the word, no."

Mikaela frowned. "What do you mean?"

The Peterbilt was silent for a moment as Optimus thought. "It is a little complicated to explain. Hmm… well—I think it is like this, Mikaela: when you are walking around, are you usually are looking ahead at where you want to go, or down at your feet?"

"Ahead…" she said slowly.

"But that is not to say that you do not know where your feet are, what is around them, or what they are doing. Correct?"

"I guess…" she said, totally confused.

"It is the same for me. I use all of my senses—some of which are well beyond human capability—to 'see' you—" and as he said this, she saw the rearview mirror move toward her of its own accord, almost as if he was using it to watch her somehow, "—as well as what is around me."

"…Oh."

What Optimus had said had made sense, she supposed. Walking was probably the closest metaphor for what driving was like for an Autobot, and walking (although often taken for granted as a simple task) was actually a complex process that involved continual information from almost every sense, just like driving was.

It was strange to think about a vehicle having actual senses akin to—or superb to—human senses. As the Autobots didn't technically have ears, noses or eyes while in vehicle form, it was easy to forget that they would still need to process information from those senses. Until just now, she'd never really even considered what they would have to make do with in vehicle form in place of their usual sensory 'organs'.

So how was it that he could 'see' her, then? Did information from her presence inside of the cab come solely from tactile sensors? Was he able to feel her sitting here, in the driver's seat? And if so, what was it like for him? She hoped that she wasn't accidentally sitting on his thigh or something weird like that…

Subconsciously wishing she had asked Bee about this back when she'd had the chance to do so in a less-awkward situation, she decided that she wasn't about to ask the Autobot leader anything more on the subject just now, just in case the answer was something that she really could have gone the entire driving lesson without knowing. There was also the question of exactly how intense _were_ Optimus's senses? He wasn't able to monitor her goddamned _heartbeat_ while she sat here, was he?

 _God_ , that would be kind of creepy!

"Okay, Optimus," she said aloud, trying to forget about this. "I—I think I'm ready."

"Great! You know what to do…"

Trembling slightly with nerves and excitement, she placed her hands on either side of the steering wheel and waited, expecting Optimus to start up his engine, like Bee usually did. But the truck remained silent and the engine did not turn over of its own accord, and after she'd sat there for a minute she realized what was happening.

"Uhm," she cleared her throat, feeling evermore awkward—did he want _her_ to do it, then? "I guess you're waiting for me to—?"

"Oh yes," said Optimus, and she could _hear_ him smiling. Was he teasing? "This is a driving lesson, Mikaela. And I have no doubts that you know very well how to turn a vehicle on."

It was the most embarrassing way he could possibly have phrased it. For the second time in so much as an hour, Mikaela felt her face burn bright red. "I-I-I do," she stammered, trying not to draw attention to what he'd just said—for all she knew, Optimus did not realize how it had sounded and would be mortified if he knew. Instead, she hastily groped for the key in the center console, not thinking to check the ignition first.

When she could not find it, Optimus asked her to check the ignition.

"Right," she whispered, feeling stupid as her fingers felt the plastic handle of the key already in place, blushing even deeper because of it. "…Sorry."

"There is no need to be sorry," he said lightly.

She turned the key all the way, but was at first confused when nothing happened except a faint _click_ as the Peterbilt's auxiliary mode was activated. This time, however, she was not to be made a fool of—she'd been inside of push-start vehicles before. It took her only a moment to locate the right button in the midst of the complicated dashboard—located directly beside the steering column.

It was a tiny, red little button right next to a much bigger red one, recognizable as the emergency brake. She poised her finger over the push-start and hesitated for only a fraction of a second, in which her heart beat a little faster in anticipation—and then, while eyeing the rearview mirror (looking at this felt more like looking Optimus in the eye in this form than anything else did)—she pressed the button.

The gigantic Peterbilt rumbled to life and Mikaela felt the frame shudder as if Optimus had been surprised, before the engine revved once of its own accord. She withdrew her finger, watching the tachometer settle from a high 1300 RPM to a nice, smooth 1.2k idle.

 _Sweet_ , she thought, admiring the feeling of power thrumming through the vehicle's frame.

It did feel really nice—Mikaela often thought that no two vehicles were ever the same, and that their idles were proof of that. Optimus's was as deep as his voice and drove right through the connection her body had with the seat, sending the vibrations straight into her. For a split second that felt like eternity, she let her eyes drift closed and just simply sat there, tracing the steering wheel with her thumbs absent-mindedly, enjoying the relaxing sensation of the idling Peterbilt.

"Are you all right, Mikaela?"

Optimus had startled her. The sexual frustration Mikaela had felt after getting into the vehicle had all but evaporated earlier due to her nerves and second-hand embarrassment from what Optimus had said about her turning a vehicle on, but now that she had relaxed it was back. She had almost forgotten that it was not simply a semi-truck that she was drifting off inside of, but an Autobot—the Autobot leader himself. Her eyes snapped back open. "What—oh, yes! Uh, are _you_?"

Her reply did not make total sense, she'd realized a moment too late—but Optimus did not seem to notice.

"Yes, I think so. I must admit, though, I was caught a little off guard by how quickly you located that button," he said, each syllable resonating in time with the flicker of the radio's cobalt-blue LED panel. "I thought I would get the better of you, but it seems I was right in saying that you really do know… what you are doing."

It was Mikaela's turn to grin. "Hah," she laughed sarcastically. "Not really, Optimus. You could say that I… just got _lucky_ and there's nothing else to it," she teased, almost hoping that the innuendo would not sail right over the Autobot's head.

"Well, if you are feeling nervous, I could start us off… you do look a little tired, after all."

Mikaela thought for a second that maybe he _had_ recognized her joke with the almost forcibly casual way he'd said this, but if he did, he did not elaborate on it. She agreed to let Optimus drive first while she watched what he was doing with the Peterbilt's controls so that he could explain a little bit about how he worked and what to do. Optimus was more than happy to do this, and she felt the Peterbilt shift into first gear of its own accord, the truck bouncing a little on its suspension as it lurched forward.

"God, this is _weird_ , you know, Optimus," she commented, watching him manipulate the Peterbilt's massive gearstick into second, the truck now cruising lazily down the airstrip toward the NEST main gate. "At least with Bee I can't—y'know—actually _see_ him shifting."

Optimus chuckled. "I can imagine it would be quite different."

"You're telling me," she said, somewhat fascinated.

"Well, you can try after we get off of the freeway, Mikaela. There is a place I know a short distance from here that I think you will find a suitable place to practice."

"That sounds great, Optimus," she said, semi-relieved that she could spend a bit more time watching him drive before she'd have to drive herself. It _did_ look pretty complicated…

And speaking of driving—the longer she spent inside of the gorgeous truck, the less she could believe that she was actually going to get a chance to try. She felt the kind of mounting anticipation that could only come from thinking about driving such a powerful vehicle—one strong enough to leave a trail of goosebumps across her arms that had nothing to do with the coolness of the air conditioning. Of all things to find herself doing on a sunny Saturday afternoon, practicing driving with the help of a giant, sentient Peterbilt certainly was not one of them—not that she was complaining in the slightest—

And as NEST officials opened the gates for Optimus Prime, Mikaela relaxed back into the seat, letting the vibration of his powerful engine sink into her—the thrill of the approaching open road, and the _possibilities_ —the depth of his voice as he oozed instructions over the radio—

"Are you listening to me, Mikaela?"

"Mmm? Of course I am…"

They had the whole day to spend together practicing—and as the enormous Peterbilt made its way through the gates and out into the scorchingly hot desert wasteland, all that its tiny, human passenger could think of was how crazy it was that the Autobot leader was really going to help her 'drive stick'—


	7. Going Fast

**Redline**

.

 **Part 7**

The craziest thing about watching a machine drive was that it was so _smooth_. As Optimus exited the NEST base by way of a nicer, much more broken-in road than the way her and Bee had come earlier, Mikaela observed that the Autobot leader was the smoothest she'd seen yet—even Bee, who didn't have to deal with a massive Peterbilt for an alternate form (complete with sixteen speeds and a lowered chassis, to boot), just didn't feel the same to cruise around with as Optimus Prime did.

The semi was just so graceful about it. It was almost poetic to watch, she thought as he upshifted perfectly every single time. Picking up speed with a low diesel growl, the huge Peterbilt rolled over the rough dirt road as easily and smoothly as though it were made of freshly-paved asphalt, his shocks absorbing every little bump.

It was mesmerizing.

It reminded her of watching her father drive, long before she had been old enough to learn herself. Riding along with Cal, she used to swear that she could feel it sometimes, even just as a passenger—through the connection her body had with the seat and her feet had with the floorboards, she'd sense Cal's ability to automatically win the 'allegiance' of any machine with just a tap of the gas and a twinge of the steering wheel. It was beyond just a regular driver/machine-type thing—he could bend the will of any automobile with the rich contrast between its cold steel and his own experienced, organic hands with just a touch, and that was goddamned beautiful.

And when it had come time for Mikaela to learn, she had bonded with them, too—as she had inherited the 'gift'. It was this certain way mechanics had with their machines that could not always be learned. It was the ability to 'listen' to them, to 'feel' them deeply—much like a sixth sense—that formed the basis for this link—something that Mikaela felt strongest with her own motorcycle, which she'd secretly named Valour for 'her' agility and seemingly endless ability to drive far, and drive fast.

It could be such an intimate feeling, sometimes—in the dead of night when she'd take her bike out for a long night ride, when the air was cool and would whip around her and the seat beneath her would thrum deeply with Valour's mechanical heartbeat, and there was nothing, absolutely nothing to stop the pair of them from going as far for as long as they'd pleased—

And it was through the depth of her skill and this knowledge that Mikaela could sense the level of sheer coordination and gracefulness that was evident in all of Optimus Prime's movements. The truck around her absolutely radiated experience. As she'd witnessed briefly in the Mission City battle, Optimus Prime had more prowess and power than any of the other Autobots—the prowess and power of a Prime—and there was just something about being completely surrounded by this feeling that made him undeniably sexy to watch.

Optimus was silent as they hit the highway. Mikaela barely registered the rather smooth transition between gritty, gravel road and the aged, worn asphalt of the interstate as he made a wide right and used the shoulder merge lane to accelerate. She felt the whole cab rumble as the semi slipped into a higher gear and emitted a heavy diesel growl that bled straight from the engine out into the floorboards, her seat, and up the long shaft of the gearstick which wobbled slightly before upshifting.

"Tell me, Mikaela," came Optimus's resonating voice over the radio, pitched an octave so deep and strong that it had no trouble being heard over the increasingly loud vibration of the engine. "Do you like to drive fast?"

They were nearing the end of the merge lane and the highway in front of them was straight for as far as the eye could see. She mirror-checked out of habit and saw that the long expanse of road behind them was clear of cars. "You have to _ask_?" smirked Mikaela, raising an eyebrow at the rearview. "What do _you_ think, Optimus Prime?"

"I think I will take that answer as a 'yes'," he chuckled. "You may want to hold on. Feel free to make full use of the handles available for your convenience."

 _Yeah right,_ thought Mikaela, remembering how _long_ it usually took rigs of this size to shift up to speed on the highway. "Excuse me, but," she replied saucily, "I don't think I'll be needing those, especially not in a rig the size of— _ohgod_ —"

With a loud roar, Mikaela found herself thrust backward into the seat as Optimus pinned the accelerator and the semi took off with so much force that the nose of the Peterbilt rose and she felt the front wheels leave the pavement for a split second. The gearstick was a blur as he upshifted faster and with more accuracy than a human ever could, and the only thing that Mikaela had the time to wonder was whether or not drag-racing big rigs was a thing—and to vow that, if it was, she'd better never tell Optimus.

"Holy _shit_!" she gasped, clinging to the aforementioned handles. Optimus just laughed.

They were moving so fast that the broken yellow dividing line appeared to blur into a single, solid colored one. They were racing through a near-endless country of golden-brown wasteland dotted with little tufts of greenish, khaki-brown plants and cacti dying under an equally-endless, faultless blue sky. The blinding sun beat down from behind them as a tail of desert dust and diesel smoke trailed through their massive slipstream, unsettling the hordes of dead tumbleweeds that resided on the edge of the highway's cracked shoulder.

"You were saying?" said Optimus, his voice carrying over the roar of his engine.

"Optimus, roll down the windows!"

As the Autobot obliged her, Mikaela felt the last of her reservations and nervousness leave her completely from the incoming rush of hot desert air mixed with the buzz of adrenaline from the Peterbilt's impressive speed. The Autobot's heavy musk that had filled the cab since she'd climbed in was wiped away by the smell of baking asphalt and bone-dry dust and Mikaela breathed in so deeply it hurt; craving the feeling of the wind on her face, she leaned partly out of the window.

"This is amazing!" she cheered loudly.

She was deaf to the world—she could not even hear the sound of his engine over the roar of the wind—the Peterbilt towered over the asphalt, dwarfing the oncoming cars it passed, and Mikaela could swear that she'd never felt more wild and powerful and free, not even with Valour. Her heart beat accelerated just like Optimus had, joyous butterflies exploding in her belly in place of what had once been unpleasant nerves—she was lost in it, caught up in the rush of driving fast.

"I take it you are enjoying this," Optimus observed, sounding pleased.

"Ha ha!" Mikaela laughed, pumping her fist outside the window. " _Hell_ yes!"

 _God_ , she thought as she finally ducked back inside of the cab, _It's been forever since I felt like this!_

The heady concoction of adrenaline and excitement pumping through her veins was enticing to say the least. And _oh,_ it just made her even more aware of just how strongly the Peterbilt rumbled as it sped along and exactly how much it caused her chair to vibrate—it made her feel recklessly headlong, and she craved more, _more_ ; she _so_ wanted to take over.

The idea of doing so became tantalizingly irresistible. Every part of her was burning for it, itching restlessly; she was unable to keep still. She grabbed at his steering wheel, stroking it longingly, her feet wandering toward the pedals as she groaned.

"Oh, Optimus _Prime_ , are you _ever_ going to let me _drive_ this thing?"

"Just a little further," Optimus said, somewhat complacently. "Have patience, Mikaela."

"Easy for you to say," she sighed, trying her best to relax into the seat, but the ever-present vibration from the Peterbilt's huge engine was still shaking the rig and she found herself baring her teeth. _God damn it._ She settled for stroking the wheel some more, with both hands gripping just firmly enough to pretend like she were going to try to take control without actually doing so. "But hurry _up_ , you silly truck."

 _Don't make me wait or I'm gonna have to beg you_ … the dirty joke went through her mind, but she thought better of saying it aloud. She'd teased the Autobot leader _almost_ enough (she didn't want to push it too far, because while Bee and Sam knew her well enough to know that she could be more than a little sassy sometimes, she just didn't know Optimus well enough yet to really try pushing his buttons). "You make it look so easy, you know, I almost can't resist," she said instead, watching him closely as she smiled suavely into the rearview.

But if the teasing bothered Optimus, he did not show it. In fact, he played along with the joke better than she had expected, never missing a beat. "Do you mean to say," he teased back in a rather low voice that somehow still managed to rumble through the entire cab, "that you find this old truck to be… 'irresistible'?"

"Oh my god." She couldn't help but flush. "Well, let me get my hands on you first, and then we'll see, won't we?"

"That sounds pretty good to me."

She almost choked. " _Really_?"

"Yes, really. As I said before, I have complete confidence in your driving abilities, Mikaela."

"That's pretty strong talk, Optimus Prime," giggled Mikaela, grinning into the mirror. "I'm starting to think that the only reason you're so well-behaved around the other 'bots is cause _they_ keep _you_ in check."

"Of course not," he chuckled. "But it _is_ very rare that I have the opportunity to… relax somewhat. It is not usually an option for me to, ah…"

"…Have some fun?"

"Yes. That would be one way to put it."

"All right, Optimus," she challenged, hardly noticing that the Peterbilt had settled back into a more reasonable pace. "That's _it_. Before we go back to base, I want you to relax and just be _you_ , you hear me? I want to see the _real_ Optimus Prime out here… no more Mister-Stressed-Out-Autobot-Boss, kay? I think both of us could benefit from unwinding a little bit. Current events have been starting to get to me, too."

The Peterbilt did not immediately have an answer for her, but the cab was filled with the very strong sensation that he was watching her closely. "It is true that I have not taken a drive to myself in… longer than I can remember," Optimus said slowly. "This may have… had a little bit to do with… why I had hoped… secretly, of course… that you would accept my offer—"

"I know, boss," she said, patting the dash in what she hoped was a comforting sort of way. "I can only imagine. That's why it's so good that _I'm_ going to drive, right? This way, you get to take some off and just relax, and I get to practice..."

"It is good with me." His calm voice was low and gravelly over the radio. "But one thing I must admit—I am surprised by the strength of your—desire—to take control and drive…" he said with a hint of a smile. "I feared that you would be too nervous to do so, but it seems that I was wrong. I have complete confidence that you will, ah—drive this stick well, Mikaela."

 _Oh, god…_ she could not blush more if she tried. It sounded so awkward, and yet so unprecedentedly attractive, coming from him. It was like he was trying to… trying to come _on_ to her, or something… and it should have felt wrong (especially as he was technically an alien, and she was currently in a relationship with Sam), but she would be lying if she didn't admit that it was kind of hot. Weird, and so not like him, but hot—she squirmed in her seat. There was no way that Optimus was _really_ trying to seduce her on purpose, was he?

"Optimus…" she said slowly. "Are you… you're not _flirting_ with me, are you?"

The Autobot's voice was suddenly stern. "…What?"

"I asked you if you were flirting with me. I mean—"

"No," he said firmly, and Mikaela was taken aback by the seriousness of his tone.

"No?"

The Peterbilt was silent for a moment. Mikaela sat awkwardly in the driver's seat as Optimus rolled up the windows. She hadn't offended him by asking, had he?

The awkward silence stretched on as she felt a wave of anxiety pool in her stomach. God, she hadn't meant to be offensive! She thought that he had been playing along with her! And now, nothing could be heard inside of the cab but the ever-present hum of the air conditioning and the rumble of Optimus gearing down as they approached the freeway exit he'd wanted to take. She couldn't help but feel as though she'd made some kind of mistake.

"I have the utmost respect for Sam, Mikaela. No matter what…" Optimus said finally, speaking as though he were weighing every word carefully. "I know that the ways of your species are not always to mate for life. I am aware that you and Sam are both very young and it is commonplace for your kind to… experience others, before you decide to bond for life."

Mikaela remained silent, trying to make sense of what Optimus was saying. She still felt so caught off-guard—it had been the last thing she'd been expecting, for him to suddenly be so damned serious in the midst of what she'd assumed to be playful banter between two friends.

"But I am Cybertronian," Optimus continued heavily. "And the ways of our kind dictate that when we bond, we bond for life. This concept of… 'breaking up', as I believe you often call it here on Earth—does not exist with us."

"…Ah."

Her reply sounded so hollow, even to herself, but it was such an intense subject that she had no real idea of what to say back that was guaranteed not to offend him even more than she probably already had.

"I would never purposefully try to come between you and Sam, Mikaela. That is not the way of our kind," Optimus explained further. "I did not mean to say anything that implied that I… that would lead you to believe something false, or worse, that would make you feel uncomfortable. And so for that I apologize. It was my mistake if I have done so."

There was a long pause. "I'm not uncomfortable, Optimus…" she said slowly.

"I am relieved."

"Good," she told him, thinking of how best to explain. "Because I don't want you feeling bad, Mister Prime. I still stand by what I said earlier—I think it would be really good if we could both just relax for a little bit, while you let me drive." She paused here to take a deep breath, and closed her eyes before continuing, "'Cause Optimus, if there's anything that you should have known about me before we started hanging out together… it's that if there's one thing I love doing, it's poking fun at you guys a bit," she grinned. "And up until just then, I'd almost swear that you were enjoying it too, boss."

"Heh heh heh," the Peterbilt chuckled as he turned left off of the freeway ramp, heading toward the low shapes of buildings nestled between two high mesas on the horizon. "Maybe, but it is important for you to understand…"

Mikaela looked at the mirror seriously and said, as sincerely as she could, "I do, Optimus. I really do. But it's okay. _Honestly_."

"Thank you, Mikaela. I appreciate this more than you can know."

Optimus had taken them to a mid-sized town called Margo, identifiable only by a freshly-painted 'welcome' sign that marked the place's outskirts. In the shadow of the big hills, the village bore signs of once harbouring a now-dried-up river that would have run directly through its midst; its dusty banks had long since been transformed into short talus slopes and its basin had been filled with deposits of scree from the crumbling rock. A rickety old bridge singlehandedly connected the northern portion of the town to the southern portion—the northern consisting mostly of a decently-sized residential district and the southern being of mixed-use industrial and commercial lots.

Approaching from the south, Optimus pulled over into an abandoned gravel lot located adjacent to a run-down motel that had a completely dry swimming pool for an amenity and a large, faded sign plastered over the office door that said that it was 'closed for the season'. The other side of the lot backed onto a somewhat-dilapidated strip mall with overfull rubbish bins that spilled their garbage onto the vacant property. The few crows scavenging amongst the debris were frightened into the air as Optimus approached, their harsh cries the only sound joining the rumble of the Peterbilt's slowest gear and the crunchy pop of gravel under his tires.

"This is a place I sometimes pass through," he explained to Mikaela, who was staring out of the window with a look of confusion on her face. "It is the only stop for many miles when you're heading west from base. It is quiet—I thought it would be a suitable place to practice."

The big truck halted dead-center of the lot with the hiss of air brakes and idled there. Mikaela swallowed, trying to ignore the way her stomach twinged a little as she ran her hands along the smooth rubber of Optimus's steering wheel. "It's perfect, Optimus," she said, and the truck revved a bit in appreciation. She watched the tachometer needle spike as he did so, and sighed as the soft vibrations spiked in pitch and frequency along with it, her breath shaking a little as she exhaled.

He was most _definitely_ a sexy truck.

"Okay…" she said breathily, letting her feet finally find the clutch and accelerator pedals. "Ready, Optimus?"

"Ready."

And finally— _finally_ —Mikaela reached up to the red button on the dash and released the parking brake, easing onto the clutch. The gearstick was in neutral—she reached over to it, sparing only a second to smirk at its overly-exaggerated size (the tip of the damned thing reached past the bloody top of the dashboard, for god's sake) and wiggled it back-and-forth. Still holding the wheel with one hand, she followed Optimus's instructions, checked the splitter to 'lo' and manipulated the stick right into the spot she'd wanted—up and over to the left, she felt the transmission hit first gear and eased off the clutch, searching for that sweet spot where she could hit the gas without stalling him out.

The Peterbilt snarled appreciatively and started forward with a lurch. As Optimus congratulated her, she found she liked the way that the big truck swayed and growled with every bit of gas she gave him. Twirling the steering wheel, she led him once around the perimeter of the lot before she raised a hand to the top of the gearstick, admiring how cool and silky the metallic cobalt-blue case on top of the thing felt under her fingertips and how it vibrated more than her seat and the mirrored floorboards beneath her feet combined.

"A-ah," said Optimus, and she noticed that the radio did not flicker with each syllable when he said this, but glowed a solid blue. "You're ready for second gear then, are you?"

"Well, you should know me well enough by now to know, Optimus…" she teased, easing the clutch in along with the accelerator as her left hand pulled gently on the shifter. Squeezing gently as she took him back into neutral so that she could drive it into second, she felt his transmission vibrate harder against her hand. "I can't resist going fast, can I?"


	8. Driving Stick

**Redline**

.

 **Part 8**

Optimus made her circle around the lot several times, letting her practice until she was capable of shifting between gears without the aid of the clutch. He would not let her go past second gear— as it was, there were still a couple of times where Mikaela had made a mistake. Once, she had accidentally stalled him while trying to get him rolling from a dead stop, and another time, she'd meant to slide him into second, but had not been moving fast enough. It did not go in—the shifter had with trembled with the guttural, hair-raising noise of a missed gear.

"Oh shit!" she gasped immediately, releasing the shifter as though it had burned her. "Sorry!"

The Peterbilt shuddered a little but then the stick slid forward into second of its own accord. "It's perfectly fine," said Optimus calmly. "Mistakes happen, Mikaela, and you are still doing well."

"Are you sure?" she asked, feeling guilty. "You—you're not hurt, are you? That sound always seems like it would be painful…"

"No. Remember who you are talking to, Mikaela… it would take more than that to wear _my_ transmission out."

The rearview tilted at her, momentarily showing off its darkened tint. It was the closest the Autobot could come to winking at her in this form.

Mikaela relaxed. Some of the embarrassment she had felt was eased by the knowledge that he was not upset. That was the most awkward thing about learning to drive with an Autobot as your instructor—if you _did_ make a mistake, not only did you have someone continually observing you who would, without doubt, notice, but you also had the potential to hurt them. Even though she knew that the Autobot leader was very tough with inhuman reflexes that were much greater than hers and that he could easily take control back before she did manage to break something, she was still cautious. She couldn't imagine how terrible she'd feel if she somehow managed to harm him.

"I just want to make sure." Mikaela redoubled her grip on the gearstick's knob. "The last thing I need is to break you somehow…"

"That is not going to happen," Optimus comforted her. "Although… you _could_ benefit from handling that a little better, next time," he teased.

She knew that he was joking, but she still could have kicked him.

"Oh, _really_?" Mikaela scoffed, ignoring the way the truck growled in response to her command to accelerate. "Well _maybe_ it would be a lot easier to shift if you didn't have such a _huge_ gearshift, Optimus Prime!"

It was immediately apparent that she had hit a nerve. The truck's engine spluttered in surprise, nearly stalling out.

 _Oh no you don't—_ Mikaela stepped on the gas, revving the engine as she smirked. _You had that coming, you god damned sassy Peterbilt_ , she thought to herself as the sheer power and vibration thrummed through her seat. _See what you have to say about_ this _—no third gear yet, my_ ass _—_

Catching him off-guard, he was unable to prevent her from upshifting. While she'd expected the Peterbilt to produce the usual low, rumbling diesel growl in third gear, she did not expect to hear the engine purring even before she'd gotten the thing in the right slot—but as soon as her fingers had closed around the shifter's knob and gripped it tightly she'd felt the truck's RPM jump without her help.

"Jesus, Optimus," Mikaela frowned, confused. "A little enthusiastic?"

Optimus chuckled hesitantly, and over the radio, his voice sounded different—there was a distinct undertone of something she could not quite place. He sounded almost nervous. "…You are not the only one who likes to drive fast…"

He had sounded _shy._

But just as this had occurred to her, she noticed that it fit with the truck's body language—the phosphorescent-cobalt glow of the radio was abnormally radiant and the dash's lighted gauges shone bright white.

Was he _blushing_?

Oh, now she just _had_ to say something to make him blush even more, if that was the case. Just to see. You know, to test whether or not she was right.

'Cause it wasn't like it was very easy to tell if the giant Peterbilt truck was bashful or not, on account of him not technically having a _face_.

"And what about being _driven_ fast?" she said.

She thought she detected the smallest spike in RPM, and checked the dash, just to be sure. The tachometer needle rose a minuscule amount, just as the light behind it flickered and then Optimus answered in a voice that was very clearly more quiet and reserved than he usually was.

"I can't say that I… see any reason as to why that would be any less enjoyable," he said.

So much hesitation was in the normally-smooth Autobot's voice, it was adorable—but something about it made her start to think.

"Optimus," Mikaela said suddenly, voicing her thoughts. "Have you ever had somebody else drive you before?"

The Autobot leader was slow to respond. "…No," he said finally. "No, I have not…"

She was so distracted by his response that she almost crashed. At the last second, she span the wheel, turning sharply to avoid running straight into the very-solid garbage bins—but she missed third gear and for the second time, the Peterbilt ground out the most horrible sound. Mikaela gasped, horrified with herself.

"Ah," she squeaked, "I'm so sorry, I got distracted, Optimus—you _really_ have never had anyone drive you before? I'm the first?" She was shocked. "I mean, fair enough… you guys probably didn't like, go around driving each other around on Cybertron… But you _could_ have had someone drive you on earth by now. You… you _have_ driven someone else around as a passenger before though, right?"

"No," the Peterbilt answered in a very gravelly, deep voice. "…But I am honored to have you as the first, Mikaela."

"Well, jeez, Optimus," she answered, feeling flattered. "Thank you!"

It made her wonder whether maybe there _was_ a flirtatious undertone to what he'd said.

The idea of him flirting with her on purpose had never really left the back of her mind even after she'd outright asked Optimus about it. She knew that the giant Peterbilt had a knack for just being nice, which would explain everything, and that he would always deny any ulterior motivations, but she just couldn't shake the feeling that there was somehow more to it than he was letting on.

Not that she was complaining. It was damn _cute_ when he said things that sounded so unorthodox coming from him just like that was, in his usual trying-to-be-so-professional, I-am-the-leader-of-the-Autobots type way. It reminded her of Sam, almost—only, Sam was a lot dorkier, and a lot more apt to put his own foot in his mouth.

 _But I am honored to have you as the first, Mikaela._

So she was the first human he'd even driven around with inside of his cab. It did explain a lot—like why she felt like he had been trying to 'show off'—apparently this was a thing that men of all species enjoyed doing to females, then, regardless of how hard Optimus would try to deny it.

But when was the last time that he'd even _been_ around a woman in a non-professional environment, then?

"Optimus…" asked Mikaela slowly, "does that mean that you haven't—god, Optimus, when _was_ the last time you were even _around_ a lady besides me?"

"…Arcee?" he pointed out.

"Oh—um, not what I meant, boss. I meant, errrrr, outside of work. When's the last time you were _with_ a lady," she hesitated, realizing how bad what she'd just said sounded. "I mean! That's not—no, I… oh my god." Her face turned bright red. "I just meant, like, hanging out? Going for coffee, or something? Not—"

The entire truck shook with Optimus's laughter. "Hah!" he chuckled before continuing in a serious tone. "I understand what you mean. And the last time I entertained the company of a femme—that is to say, a female, in your terms—while I was off-duty, was a very, very long time ago. Long enough ago that our planet still existed, and was still habitable."

Mikaela's foot accidentally pressed rather hard on the accelerator, and the truck rumbled forward noisily.

" _You haven't been on a date since_ then?" she asked, shocked.

Optimus proceeded to explain that he'd mostly just been too busy—there _was_ an Autobot 'femme' he'd had his 'eye' on for a very long time, and he was _pretty_ sure that the feeling was still mutual—but they were at war with the Decepticons, and not only did they just not have time for such things, but romantic interests posed a risk he could not take.

"I do not like to admit this," Optimus sighed heavily over the radio, "but sometimes, I do wish it was different. As you already know, I have little time even for myself these days… I must stay focussed… even if it is, ah, a rather _lonely_ lifestyle."

Mikaela immediately felt a sharp pang for the Autobot leader. What must it be like, to live your days with nothing but the promise of endless war? She knew that Optimus did have things he looked forward to, and he always had the company of the other Autobots and the handful of humans he'd managed to befriend, but she couldn't imagine how alone he must feel in the downtimes.

Optimus Prime had clearly known almost nothing aside from responsibility for years. The heavy weight of the Autobot's survival weighed on him relentlessly. It made her feel even gladder that somehow, _she_ had been the one to make him realize how badly he needed to take a break, even if only just for the afternoon.

Seeking to comfort him, she reached out and brushed her palm against his dash, letting the pad of her thumb run along its underside, trying to put everything she was feeling into the action.

He sighed even more heavily, and she felt the entire vehicle shake.

Even just the touch could make him tremble, she realized. It was heartbreaking to think of him as being so starved for affection. It was so clear to her now, not only why he had been so eager to take her out to practice driving, but why he'd seemed to enjoy her company so much (even the teasing comments—which he had done a fine job at throwing right back at her thus far) and why he had seemed to share so deeply in her excitement.

The Autobot leader was just undeniably _lonely_.

"I'm so sorry, Optimus," she whispered, still running her thumb under the lip of the dash. "I wish there was something I could do…"

She wanted so badly to do something to console him. It would have been so nice to hug him—but how could she hug a giant Peterbilt truck?

"Forget what I have said, Mikaela," he said in a would-be cheerful voice that instead came across as quite hollow. "It is not your fault. It is not anybody's fault, but simply the way fate has fallen. But _you_ … you have done wonders to help so far today. I am in your debt…"

"Oh, shush. You already know that's not true. This was all about _you_ helping _me_ , not the other way around."

He was silent for a moment. "…Thank you, Mikaela."

But somehow a simple 'you're welcome' didn't feel like it was going to cut it. Still partly lost in the aftermath of the adrenaline surge she'd experienced earlier and overcome with emotion, she found herself leaning forward into the steering wheel. Her body was reacting of its own accord and before she knew what she was doing she had squeezed the wheel against her chest as tight as she could and had planted a small, gentle kiss to the top of it.

"Oh my—" Mikaela gasped in surprise as she had accidentally triggered the horn with the tightness of the hug (or so she _thought_ she must have, even though in reality she hadn't noticed herself gripping him _that_ hard), and let go immediately in embarrassment. "Ah… whoops, I— _ahhhhhh—_ "

Having let go of every instrument she was supposed to be handling, the truck span out of control before she'd thought to remove her foot from the gas—Optimus took control back in a nick of time, narrowly avoiding running straight into a chain-link fence by slamming on the brake.

"Shit," Mikaela panted, trying to catch her breath as the nose of the Peterbilt stopped inches from the fence. "Shit, shit, holy shit, I'm so _sorry_ …"

"Primus…" came Optimus's voice, and she noticed that he, too, sounded breathless. "That was—I—"

"I know," she choked, holding her hand against her heart. "I almost _killed_ us."

Optimus was confused. "What?"

"What d'you mean, 'what'?"

"I mean, I, ah—I didn't expect _that_ —"

Mikaela stared at the rearview. "Yyyyyeah, me neither," she said, also confused. "Are you feeling okay, Optimus? I didn't hurt you—?"

"I… no, Mikaela, I am not hurt. Never mind—I was just… _surprised_. By your kiss, that was all."

She felt her cheeks burn red-hot. "Is _that_ what's got you all flustered?" she laughed, relieved. "Hasn't the _big, bad_ Optimus Prime ever been kissed on the steering wheel before?"

There was no doubt about it this time— _all_ of the dashboard lights flickered, and the radio dial suddenly rotated to play an array of static interference and jumbled-up clips before Optimus's voice broke through. "N-no, definitely not," he said jerkily.

"Glad I had the chance to fix that, then," she grinned evilly before slapping her hand rather enthusiastically back over the knob of the gearstick and squeezing, ignoring the way the rig's windshield wipers flicked on and off once as she did so. "So! Are you gonna let me take this thing out on the _real_ road or what, boss?"

"If… if you are sure…"

It was adorable, she thought, the way that the big, huge, somewhat intimidating Autobot leader's rock-hard exterior was cracking into a shy, bashful mess and it was all her fault. In the back of her mind, she thought of Sam, and how he'd probably be uncomfortable with her teasing the Autobot so much—but Sam was not here, and it was all in good fun… it wasn't like she was _serious_ about it, or anything.

Just 'cause deep down she found him super sexy didn't mean she was about to lose her cool...

Mikaela had self-control, even _if_ it was hard to ignore that the Peterbilt would rumble her seat in just the right way…

What was a little more fun, anyways? A little more fun wasn't going to hurt anyone, she thought as she slid the transmission into third and tweaked the steering wheel, heading for the gravel lot's exit.

She'd just drive him around town… just to the other end of it and back, once… and then back to the highway… and then maybe, a long time later, back to NEST headquarters…

After all, it was only two o'clock, and Optimus had promised her to be out at least 'til sundown…


	9. Distracted Driving

**Redline**

.

 **Part 9**

The great big Peterbilt rumbled down Cliff Street toward downtown. As it was mid-afternoon on a beautifully sunny Saturday, many of the townspeople had taken shelter from the searing heat by hiding indoors, and it left Optimus and Mikaela with a fairly clear road ahead of them. The few people who they passed by could be seen reading or snoozing on front porches, under shady awnings, or else splashing around in the only overcrowded public swimming pool the place possessed. Quite a few of these people stared at the truck as it passed by.

Inside of the cab, Mikaela had started to sweat again, and this time, it wasn't from nerves. The repetitive motions she was making with her feet on the pedals and her hands on the gearstick and wheel were quickly becoming second-nature; she felt a great deal more confident than she had from when she'd first rolled Optimus into gear. She was becoming a lot better at eyeing the tachometer and listening to the truck to sense when exactly to shift gears without using the clutch. She hadn't had to use the pedal at all except to get him started the past couple of times, and she was rather proud of that fact.

No, she wasn't sweaty because of that—it was because she was simply too hot. She could have sworn that the truck's air-conditioning had become almost nonexistent. While she hadn't asked him to turn it down, she didn't think that it was a problem with his system, either. She seriously doubted that an Autobot such as himself would have any trouble keeping cool, even though the heat rolling off the immaculate flat top of the semi's hood was visible in waves. Prime's cooling system should have been more than a match for a long drive on a fine summer's day.

So what was the problem, then?

It wasn't _her_ , was it? She'd been feeling, ah, a little bit 'frustrated' lately, but who could blame her, really? The damned semi vibrated like—uh, _well._ Suffice to say that it… vibrated sufficiently, actually, and it wasn't like she was getting laid a lot these days. Especially not with how busy Sam had been lately and how downright interfering his parents could be—and the attraction she'd just recently realized that she'd been feeling toward the Autobot leader did not help matters either.

God, _sex…_ the very idea of it was making her warmer. She tried to put the thought out of her mind, instead reconsidering that the spike in the cab's temperature had nothing to do with her. Because as hot as she was, she knew that it wasn't the only reason why she was starting to feel so sweaty…

 _No_ , _he's definitely turned it off, or something_ , she thought, stopped at a red light. Feeling increasingly uncomfortable and restless (particularly because once she started thinking about fucking, it was especially hard to _stop_ thinking about it when she hadn't done it in god, what, a month? Or more? Shit), she squirmed in her seat, too distracted by mentally playing out brief scenarios of rough sex to notice the way her movements made her already short skirt ride up to the very top of her thighs.

"It's getting a little hot in here, boss…" she muttered as casually as she could, trying her best not to make the Autobot feel guilty, just in case he _had_ actually turned off the air-conditioning without asking her first. "I could use a little more cold air, if you don't mind..." she grimaced.

"Duly noted," he answered pleasantly. "I will decrease the ambient cab temperature to something a little more comfortable, then."

"Thanks, Optimus."

 _God, I need to get laid,_ she thought yet again as she gritted her teeth, absent-mindedly wrapping her hand around the exposed metal length of the gearstick in preparation for the green light and foregoing the protective knob as she was tired of reaching all the way up to the top of the bloody thing to shift every single time. It was just so impractically _long_ —it was ridiculously thick, too, she noticed as she wrapped her fingers around it (she could just barely touch the tip of her middle finger to her thumb). Why did the semi needed such a large shifter was beyond her.

She was in such a state that she could _almost_ (scratch that, definitely) appreciate how— _phallic_ —the large metal fixture looked, sticking out from the center of the cab. The placement, along with its unreasonable length and particular shiny metal thickness could definitely pass for a robot's, well— _at least I'd know he's not compensating for anything,_ she grinned at the mental joke.

The truck's engine had choked when she'd touched it and as the light turned green, Mikaela eased onto the accelerator. She was surprised to feel the RPM rev quite a lot higher than would be expected for how much gas she was giving him as she shifted, making the Peterbilt jolt forward with a lot more force than she'd meant him to.

"Uh…" said Mikaela awkwardly, glancing down at her hand on the gearstick. There was no way that she'd done all of that by herself. Had Optimus—had he revved like that, because she'd touched the smooth metal of the gearstick opposed to the protective casing at the top? Surely not—obviously she was just being paranoid and perverted, having gone so long without getting laid and all…

Unsure if maybe she had done something wrong, she fixed the Autobot's rearview with a look of concern. "Whoa there, boss," she said. "Are… are you doing okay?"

"My mistake," Optimus replied in an oddly breathless voice. "My mistake, Mikaela, I… I must say, in my defense, that this is taking a lot more… _concentration_ … than I had previously thought it would."

He also sounded awkwardly annoyed with himself—and it made her feel like she'd crossed some kind of invisible boundary of his by accident.

Mikaela felt her stomach plummet as she remembered how worried she'd been before she'd got to base that driving one of the vehicles would be a bad experience for the Autobot in question. Bee and Optimus had both placated her concerns in their own way to the best of their abilities, but here was outright proof that it was affecting the Autobot leader in some kind of undesirable way. Even he could not deny the displeasure in his voice—there was something about what she was doing that he did not like and he was far too noble to tell her, and Mikaela was not okay with this.

"Oh god, Optimus, I'm sorry," she said immediately, pulling the rig safely to the shoulder of the road so that she could fully concentrate on explaining. "I've been so stupid. I _knew_ I shouldn'tve gone with Bee's idea to drive one of you guys around—I tried to ask him, how bad would it be? I mean… it's got to be super uncomfortable and weird, right? You guys aren't exactly built to have someone else taking control—"

But Optimus did not let her finish. "That is incorrect," he rumbled over her, sounding pained as Mikaela's slick palm slipped against the shifter's length as she let her hand fall away from it. "Un—uhh. 'Uncomfortable' is not the exact word I would have used."

Had the Autobot's voice just _hitched_ when she'd done that, she wondered to herself. His reactions were a lot like someone who was being touched in a somewhat pleasurable way and yet trying not to let on to it, but this was impossible. The Autobots had physical sensory receptors inside of their alt-modes, this was true, but here was no _way_ that he could feel her touch with the goddamned _gearstick_ , was there?

"What _is_ the right word, then?" She asked Optimus. She was beginning to feel very confused and more than a little curious…

"Ah," he said, his voice having not lost that pained, semi-awkward quality. "Well, 'distracting' might be a better word…"

She could have sworn that the Autobot had smiled at her, and the overwhelming feeling of being flirted with that had never wholly left her since she'd entered the Peterbilt's cab was on her again. Butterflies filled her stomach.

So she was _distracting_ him, was he?

"Mmmmkay, so…" she said slowly, weighing every word, "that's not exactly a _problem_ then, is it, boss, as I'm the one driving? Leaving you free to be as _distracted_ as you please... Unless of course, you'd prefer me to stop—"

" _No._ " Mikaela was startled by the forcefulness of the word. "Uh, I mean, unless you have had enough—I did not mean to imply that I find this procedure… _undesirable_. In fact, it is quite the opposite."

Mikaela raised an eyebrow at the rearview. "Ooo," she grinned mischievously. "Is that _so_?"

"Ahem," Optimus simulated a throat-clearing noise. "Yes. It feels rather, ah— _nice_ —to be able to let someone else take over and drive, for once."

She couldn't help but smirk as her shoulders shook with a huff of silent laughter at how awkward and god damned _innocent_ the Autobot sounded when he'd said this. "Okay, boss. Just as long as you'll tell me if any of this gets a little too much for you, then."

"You have my word."

A rather long silence stretched between the two as Mikaela pulled off of the shoulder and continued driving through Margo's downtown core. As they crossed the rickety old bridge that passed over the rubble-filled riverbanks, she pretended to be very interested in the town's southern-esque architecture to avoid conversing with the robot, her mind far too full of what Optimus had just said.

So, driving him wasn't exactly how she had guessed it would be for him—instead of the Autobot finding the experience unwelcome, he had fully admitted that it was at least a little enjoyable. But what exactly this implied was what had Mikaela confused—on one hand, she was pretty sure that Optimus would _tell_ her if driving him (or, for good measure, touching any part of him whatsoever) was akin to anything more than a relaxing backrub (to use the same metaphor Bee had previously used)… especially because of how much he respected Sam. But on the other hand… she knew well that the robot was the exact kind of person who would—perhaps foolishly—consider himself above such whims like desire and potential lust until it was too late.

Mikaela shook herself mentally. Was she _really_ sitting here wondering whether the sentient Peterbilt truck she was currently driving was feeling lustful toward her or not? God, what a weird thing to wonder… and about _Optimus Prime_ , nonetheless, the endlessly stoic and collected leader of the Autobots…

And she was seriously considering that maybe _she_ was making him lose his cool? As _if…_

No, what was more likely was that the 'bot simply was, as Bee had said, enjoying a nice relaxing experience out with a good friend. And so was she, she was doing nothing more than sharing that, ah, soothing, tranquil experience, with him—a _friend_ —who, incidentally, could probably feel everything she did, and every which way she moved…

Optimus Prime, who could also most likely sense every molecule of her skin touching him and practically feel the whorls of her fingertips against his gear stick… and was probably continually assessing her heart rate, her breathing rate, etcetera, through that contact pressed gently against the smooth chrome shaft of the thing…

Aaand who could probably _also_ feel the naked back of her thighs sticking to the burgundy leather of the driver's seat as her skirt rode up ever higher while she drove along…

 _Okay,_ she told herself. _Think of something else…_ anything _else…_ she tried to make herself more interested in the residential neighborhood surrounding them than she was. The small-side street was barely wide enough for the massive truck…

But she was disappointed—not a soul could be seen, not even on the shadowy porches of faded houses packed with mismatched chairs and tiny decorative potted cactuses, some of which were partially obscured by hardy vines with trailing feelers clinging to sheets of lattice and chicken wire.

The street was dead until eventually, the pair of them came to a little group of children who were playing a haphazard game of hastily-drawn hopscotch off to the side of the road with broken sticks of rainbow sidewalk chalk. They had to be no older than eight, Mikaela guessed as she watched them— there were two girls (who looked to be sisters, with identical curly locks of golden hair), and one dark-skinned boy who was clearly the youngest of the lot.

It was the boy who noticed the approaching Peterbilt first. He nearly tripped over himself in his hurry to point out the truck to his hopscotch companions—Mikaela couldn't help but stifle a giggle as he leapt up and down on the spot, quivering with excitement and pulling at the girls' t-shirts and pointing. It was heartwarming.

The truck had already been going pretty slow due to the nature of the road they were on, but as she watched she felt the truck downshift on its own to barely a crawl. Mikaela saw a switch on the dash—one marked by the little imagine of a headlight shining—flick to the 'on' position and knew that Optimus had turned on the Peterbilt's many accessory lights.

Despite the brightness of the day, Mikaela saw the reflection of the rig glowing bright neon blue against the nearest house's dark window panes. Yet again, Optimus Prime's apparent weakness for showing off was showing through—he just couldn't resist, could he?

And the children loved it—the young girls cheered and the little boy was so excited Mikaela saw his eyes nearly pop out of his head.

"Aww…" she murmured affectionately, more to herself than anything. "That's _so_ adorable!"

"Mikaela," said Optimus, and the tone of his voice was a dead-giveaway that he also harboured a soft-spot for human children. The semi was totally into it, and she could darn well _hear_ him melting through the radio! "Do you see that cable hanging down in the top left corner of my windscreen?" he asked her.

"Yeah," she said, eyeing the slender black cord.

"Pull it."

It was pretty obvious to Mikaela what the cable was for even before she followed his instructions. The horn that she had accidentally triggered earlier (or, rather, the horn that she had the increasing suspicion that _he_ had triggered earlier in his surprise when she'd kissed his steering wheel) was no more than the typical city-horn that every vehicle was equipped with by law. But big rigs were also designed with a much louder equivalent—the air-horn—and, although she'd heard Optimus Prime use his in battle before, she had never been so close to him when he sounded it.

And when she pulled it—she pulled it twice, for good measure—she had to admit that the loud, oddly _dominating_ sound went straight from where it reverberated inside of her chest right down into her groin, because it was just so damn _impressive_ and _attractive_ and… and _all-encompassing._ Her mouth went dry. She'd always liked the sound of a rig's horn, but hearing it while inside of the cab, so close-to, and actually _pulling_ the thing herself—it was a whole different experience, and a lot more intense than she'd previously expected it to be.

"Holy fucking shit," she'd muttered appreciatively to herself, her jaw practically on the floor. "That is _so…_ "

She barely even noticed how the children down on the sidewalk were cheering and clapping enthusiastically as she had rolled past. Without even thinking, she pulled the horn again out of sheer desire to hear it again and breathed deeply as the blood rushed to her face.

Was it just her, or was the cab becoming increasingly muggy again? "That is _so_ hot," she whispered, licking her lips.

How could a vehicle make her feel so sexually frustrated? _Dang it all, Optimus Prime…_ it was his fault. Because _this_ Peterbilt was doing things to her that she had previously thought no vehicle would _ever_ be able to do…

But if Optimus had heard her comment, he had ignored it. Breathing out a long, shaky sigh, she blinked hard and tried to concentrate on driving to the end of the street very slowly, minding the parked cars on either side of the road (it really was a tight squeeze for such an enormous truck). The sensation of pooling warmth and tension that had started with the air-horn was distracting in the worst possible (or maybe the _best_ possible) way, and she willed it to fade—but either her subconscious was making her rev the Peterbilt at a higher RPM than she'd meant to, or Optimus was doing it on purpose, because before she knew what was happening the rig was absolutely _purring_ under her even _worse_ than before and it was making her whole entire goddamned seat vibrate.

"God damn it, shit," she gasped, gritting her teeth as she worked the clutch and gripped the shifter's rod with sweaty hands that shook and slipped accidentally as she locked into second and then down to first, finally hitting neutral and stopping just before a stop sign at the end of the road. Could he be _any more_ tempting if he _tried_?

"If you need a break, we can pull over," the truck suggested in the deepest, most rumbly, _gravelly-_ and-yet-maddeningly-innocent voice she'd heard him use yet. "Or if you are in need of some assistance… I am, as always, more than happy to help."

She could have sworn he'd revved briefly while he said this, causing the tachometer to register a slight hiccup in the RPM idle, and she could have _killed_ him for doing it.

"O-oh, hah," she laughed forcefully, trying to maintain a level voice. "N-no. I-I'm doing just fine, Optimus. You just—uh, well… you remember what you said to me, a little while ago, right?"

"Which part?"

"Um, about you finding me driving you around kind of distracting?" she winced.

"Yes, and what about it?"

"W-well," Mikaela choked, face burning bright red, "I'm… I'm finding _you_ a little distracting, too, to be honest."

She'd been at a dead stop, hands off the shifter and feet on the brake and the clutch only, but she felt Optimus shake hard as his engine spluttered and died. The rig had utterly stalled all by itself—Mikaela plunged her finger into the starter button on the dash reflexively and the engine coughed before turning back over. She'd removed her finger right away, but the tachometer needle still spiked again anyway, causing the truck to make a long series of coughs just as Optimus's voice came over the radio.

"R-really, Mikaela?" he choked. "Is… is that so?"

Her heart beat was beginning to hammer inside of her chest as recklessness seized her. She'd never felt so _wild_ , and she found herself saying in a downright seductive voice, "Yes, _Optimus Prime_. And you should know something else. …I've always thought you were a very _sexy_ truck…"

His RPM dropped so suddenly she almost thought he'd stall again—but then rose back to a semi-steady idle, oscillating with pulses that were a little higher than normal, almost like a quickened heartbeat. The low vibrations bled straight through the floor of the cab, up her legs and up into her seat and right into her groin where she felt her own heartbeat throbbing.

"… _Well_ then, I am flattered…" Optimus positively purred over the powerful rumble of the Peterbilt's idle.

Mikaela licked her lips thickly, trying to focus. Jesus, they had a task to be doing, and here they were, becoming increasingly flirtatious? Or, well, _she_ was. She still didn't know for _sure_ if the Autobot was being so suggestive on purpose or not… but then again, he'd just _stalled_ when she'd said she found him distracting!

"Ahem," Mikaela cleared her throat pointedly, breaking the heated silence that had stretched between the two. "We're supposed to be driving, remember…" she raised her eyebrow in the rearview.

"Hm, yes…" said Optimus, somewhat guiltily. "Yes, we are…"

 _But… then again_ —she thought, as she eased out the clutch slid the truck back into first gear, buzzed with arousal and all-too-aware of the way the entire rig trembled as it moved forward— _driving is the thing that got us here in the first place…_


	10. Redline

_A/N: this part has sexual content..._

 **Redline**

.

 **Part 10**

She hit 35 miles per hour in eighth gear. The residential neighborhood they had passed through had opened up into a wide, perimeter road that wound all the way around the city, like a ribbon of charcoal-black baking under the hot sun—it was as smooth and velvety under the semi's tires as only freshly-paved asphalt could be. A nice, wide stretch of road, it was perfect for driving a little faster on.

Settling back into the seat, Mikaela narrowed her eyes in determination, breathing in a deep breath and willing herself to concentrate on the road and _not_ the Peterbilt. The tension she'd felt building up inside of her would have to wait for some other time—she had a job to be doing, after all. It took all of her resolve, but she managed a series of impressive upshifts that hit each gear perfectly as fast as she could without comment—but she could not ignore the way the sharp acceleration made the Peterbilt's engine groan. _Good god,_ she thought to herself. She was only in eighth gear, it wasn't even like she was putting the truck through its paces and yet—it was almost like he was _trying_ to be sexy on purpose…

"You're getting a lot better at this, Mikaela." Optimus's voice was as heavy and breathless as it had been right after he'd stalled. "I am— _impressed_ —"

Mikaela chose not to comment, instead raising one eyebrow at the rearview with a small, shy smile. The truck rumbled along noisily at a steady speed, but the rumbly quality of the Autobot leader's praise had sent a lance of heat through her that had nothing to do with how warm the cab had become, despite her attempts to ignore it.

The air conditioning inside of the cab was beginning to feel almost nonexistent. Mikaela pushed several loose strands of hair back off of her sticky forehead and behind her ears, squirming a little in discomfort. The combination of the truck's warm air and her own _feelings_ was making her begin to sweat—she tried very hard to ignore the way her legs stuck to the smooth, squashy leather of the driver's seat when she moved. It was only making her skirt ride up even _further_.

"God…" she whispered to herself, reaching out to fiddle with the climate controls, but they'd already been maxed out. At the same time, she became conscious that the leather seat beneath her was beginning to feel as though it had been baking under the hot sun. Had she accidentally triggered the seat warmer?

Confused and distracted, she glanced down at the center console, trying to search for the switch while keeping one eye on the road, but if it _was_ because of the seat warmers, she couldn't find the damned controls. "Optimus…" she said in a hesitant voice, half-given up searching. "Um, you don't have seat warmers in this thing, do you?"

"Mmm, no," purred the Peterbilt, his voice low-pitched and sexy. "Why…? You aren't cold…?"

"No," she muttered quickly, her eyes snapping back up to the dashboard to check the rig's temperature gauge instead. "No, uhh, it's actually… pretty warm in here, to be honest." The coolant levels seemed fine, but Optimus's temperature was elevated, she noticed. "Are… are you okay? I think you're running a tiny bit hot, boss…"

The semi was only vaguely surprised. "Oh, yes, sorry. You are right…" he said distantly. "That is… nothing to be concerned about, Mikaela. I can fix that. Here—"

There was a whirr from deep within the engine, and after a few moments, air began to pump through the vents again. Only, the breeze was not nearly as cold as she had been expecting. It was a rather warm draft, and Mikaela yelped in surprise.

"Whoa! Jesus, that's not cold at all!" she frowned. "What the hell is wrong with your air-conditioning?"

Optimus was obviously confused and embarrassed. "Oh, slag. That is not very cold, is it."

"Definitely not!" she fanned herself. "I mean, I _know_ I said that you're hot stuff," she teased, cocking an eyebrow in the rearview. "But I didn't really mean _inside_ …"

As she spoke, she had released the gearstick and trailed one long, slender finger down part of its shiny length, watching with lazy satisfaction as the dash lights flickered and the highbeams flashed by themselves, contemplating his reactions. "Um… uh," choked Optimus in an uncharacteristically weak voice, lost for words. "That's—I—"

But she didn't give the Autobot a chance to recover. For she understood, now, that he could physically _feel_ every little touch she made against his interior, as though she were touching his skin. And that the smooth metal parts of him that were lacking in protective coatings of plastic or rubber were obviously more sensitive. As she realized this, the nearly irresistible tension she'd been fighting peaked in one long, slow wave—how could she _resist_ teasing him? He was so damned _cute_ when he was flustered…

If he even _was_ actually flustered…

Forgoing the use of the steering wheel's rubber cover, she wrapped her hands around its chrome spokes to steer instead, winding her fingers around the gearshift with a devilish smile and a wink at the same time—because honestly, it was only fair. If _she_ had to sit here and be subject to the tantalizing vibrations of such a big, powerful truck all afternoon, she was _damned_ sure she was going to return the favor!

Careful to touch as much of the surprisingly warm , exposed metal as she possibly could, Mikaela made a left onto the road that would take them back over the bridge and toward the freeway, savoring the way the entire rig shuddered as she did so. Warmth pooled in her belly as she groaned internally, half-hating him, caressing the middle portion of the gearstick as she bit her lip.

 _This goddamned truck… I blame him for_ everything…

"Uh—Mikaela—" Optimus's voice was full of an almost innocent disbelief. "Are—are you sure you want to… ah—"

But she took this moment to shift into ninth gear, cutting him off as she slammed the stick forward roughly into the gear slot and the whole Peterbilt trembled with a deep, growling noise so strongly that she was momentarily concerned that he might just collapse the rickety old bridge they were crossing with a decibel like that.

 _I almost hate you, you know that, Prime?_

"—um, go faster," Optimus finished in a very weak voice.

"Go faster?" she challenged with all the determination in the world. "Why, Optimus. If you say so…"

Fire flashed from her eyes as she twisted the steering wheel, making a sharp left onto the road that would take them back to the highway. A very long, very straight line of asphalt stretched out before them, cleaving the near-endless expanse of desert wasteland in two. Without a backward glance, Mikaela and Optimus left the city called Margo and headed straight south on a beautiful empty road with no obstacles or turns for miles until they'd hit the interstate.

It was perfect.

It was the chance she had been waiting for—the chance she wasn't sure she should take. It was her golden opportunity to test if what she was doing to the semi by driving him, and touching him how he hadn't been touched by human hands before (when he was so clearly starved for any kind of physical contact), was actually causing him to lose his self-control almost as badly as it was making her lose hers. She fingered the splitter switch on the side of the gearhead, unsure, wondering whether or not she should wait until they hit the highway to start revving him up again, or if she should even continue driving him at _all._

She _so_ wanted to. And it wasn't just because she enjoyed driving fast—but also because Optimus's reactions to her touches were an undeniable turn-on she hadn't even known she'd had. Because there was no mistaking the Autobot's body language, not even with how hard he was trying to hide it (which was probably hard to do in the form of a monstrous, beautiful semi with lots of bells, lights, and whistles)—she was _dead_ sure that he was enjoying this more than she'd ever thought he would.

That was what she _wanted_ , anyways. To explore him, to experiment a little with his chassis, his 'body'… heck, what kinds of buttons _wasn't_ she willing to push in this thing? It wasn't every day she got to do that with any kind of boy. God, the opportunity felt so _rare_ these days, and let alone with someone so… _unique._ Just the thought of doing—well, _him_ had her heart pumping faster with nervous excitement.

God, though, what would Sam say? What the fuck would he think of her if he could see her _right now,_ if he knew what she was doing and that she was _seriously_ considering all of this?

He'd be fucking pissed, and she knew it.

But it wasn't _all_ bad, was it? Her actions would be pure, even if her motivations were not. She wasn't going to do anything except keep driving the rig.

 _No,_ she thought, pushing the sensation of guilt pooling in her stomach away. She had absolutely no proof that any of this was as dirty as it felt. It was just driving! And even though she didn't know much about Autobot sex (aside from the fact that they obviously _did_ have the capabilities to …interface), she was pretty sure that driving did not qualify as … _that_. No matter how… potentially intimate the experience was.

God, they were so close to the freeway, she could almost taste it. Mikaela's right hand continued to gently stroke the metal rod of the shifter as they approached the onramp, and she smiled to herself as she watched the Peterbilt's tachometer needle twitch a little in time with each touch, each flicker more and more obvious than the last.

"Hell yes," she muttered, talking to herself as the shape of the freeway overpass loomed ever-closer in the distance. "You ready for this, boss?"

The tachometer spiked visibly in reply as she felt yet another wave of heat roll through the cab. At the exact same time, a brand new and unexpected sensation (one that she could not place, except to say that it was kind of tingly) swept over her, making the baby hairs on the back of her bare arms stand on end. Little goosebumps erupted there.

 _Okay_ , she thought, rubbing her arms. _There's no way I'm imagining this anymore. Optimus Prime is definitely turned on, too…_

"Mikaela."

Optimus's voice was suddenly serious over the radio. "Something wrong, boss?" she asked him.

"Not _wrong_ , but…" he hesitated. "I would be lying to you if I said I did not want this, Mikaela… however, there is something, something _important_ that you must know, before we—"

Mikaela held her hand up to the radio display. "Shh," she told him. "I already _know_ , boss."

He paused. "…You do?"

"Well, yeah," she said as slowly as the mounting anticipation inside of her would allow. "Don't you think I can _tell_? I mean…" she whispered, her eyes flashing in the direction of the dashboard's many instruments. "It _is_ pretty obvious from here what's going on… it doesn't take a genius mechanic to figure it out. I never thought I'd see the day where I'd say this, but I _thiiink_ I've found myself alone with a _horny_ Optimus Prime," she smirked.

"Ah," he said, clearly a little unsure of what to do or say next. "Okay. That, I was not expecting. I thought I had been subtle—"

"It's okay, boss," she interrupted in the most comforting way she could think of, patting the dashboard affectionately. " _Really._ I remember what you said about how long it's been. I can't even _imagine_. I haven't gotten laid in like, a _month_ ," she groaned (squeezing her thighs together tightly as her subconscious went into overdrive at just the _thought_ of sex, imagining many very, _very_ dirty scenarios that involved—of all _godforsaken things_ —the fucking Peterbilt's gearshift), "…and I'm _dying_."

The appreciative rumble the truck gave and the tone of his voice were semi-contradictory. "I am sorry," he rumbled weakly. "I thought… that I was far more capable… of resisting these, uh—urges—and for that, I apologize. I would never have… ah, offered to do this—"

But Mikaela had had enough. They were _ever_ so close to the highway and she just couldn't take it anymore! _When_ was this stupid truck just going to _admit_ that he wanted to be fucked and let her—well—do the best at it as a tiny little human driving an Autobot big rig could?

" _Optimus Prime_ , do you _want_ me to _drive you_ or _not_?" she demanded.

"Mikaela!" cried Optimus, equally desperate. "You _must_ understand! If I—if _we_ continue like this, if we keep going in this _direction_ —I am afraid, _so afraid_ of reaching a point that… _neither_ of us… will be able to turn back from! Do you understand this? You must understand!"

His words were heavy, but Mikaela had already decided. She knew what she wanted. She wanted _him_ —it had been the same ever since she'd first heard the decibel of his voice, since she'd first seen the way his low chrome visor shone under the sunlight, felt the vibrations of his power source spreading up her legs—she'd wanted to shatter his stoic exterior for _so long_. She wanted to do it, and she wanted to do it _now._

Of course there were a million reasons why she shouldn't—a million reasons why she should have already pulled over and asked Optimus to bring her home—but something inside of her had snapped clean in two and she just didn't have the _willpower_ anymore. The reckless daring brought on from an afternoon chock-full of diesel fumes and pure horsepower had sent strong surges of adrenaline through her veins and she found her resolve completely shattered by them.

And at that precise moment, she gripped the wheel tightly with one hand and the shifter with the other, groping for the next, intoxicating gear— _fucking hell, I cannot believe I am going to do this.._.

"I want to drive you _insane_ ," she all but growled, ignoring the way the rig shuddered in appreciation. "I _get it_ , okay? God, don't _you_ get it? I want to drive _you…_ I've wanted to drive you hard and fast for _hours_ now… I'm going to go fucking mad if I don't, and I think I'm right when I say that you feel the same way, Optimus Prime!"

The heaviest silence yet swept through the cab, and for a moment, nothing could be heard but the ever-increasing hum of the truck's RPM. "But what about Sam…?"

"Forget Sam!" she shouted. "Optimus, I want _to fuck you_!"

"B-but!"

Mikaela was ready for him. They vaulted over the overpass, and she took this precise moment to shift gears—her thumb, which had been riding the lip of the smooth outline of the splitter, flicked it with a very satisfying little _click_ before she roughly shifted back into the first gear slot, now toggled for tenth. Optimus's voice stuttered so badly over the radio she could hardly make out what he'd said.

"— _P-p-primus_. I had _no idea_ t-this would _—_ oh. Oh, _no_. _"_

She'd hit the merge lane clocking almost sixty in eleventh gear, feeling the heat from the Peterbilt's engine ooze through the cab exactly as a fresh wave of heat shot straight through her body to her groin. She felt the gear stick twitching, like it wanted to eject itself out of the gear slot but she was too strong for him—she held it there, even while the Autobot made a grinding, almost guttural sound, very similar to the one he'd made when she'd missed a gear except different—more frantic.

Twelfth gear. With half her mind still on driving, she moved over the dotted white line, groaning to herself. Had she thought she was turned on _earlier_? It was nothing compared to how she felt now—the mounting anticipation was at its breaking point and it was all that she could do to keep the rig steady as she felt the shifter vibrate even harder under her hand. It was growing hot, too, making her feel like she was holding onto some kind of giant, mechanical dildo that had been left outside in the sun.

 _Great analogy,_ she smirked.

"Y-you must slow down." Optimus's voice was faint over the radio, a pop of static interference evident in the harsher syllables. "Mikaela, if you… if you keep doing this, I… I-I'll—"

"You'll what, boss?" she asked in a dangerously sweet voice, guessing at what the Autobot leader was going to say next.

And then, sure as hell—

 _"You're going to make me overload_."

"Is that a challenge?" she flashed him the most seductive smile she was capable of. "Because, Optimus Prime…" she was tracing the length of the gear stick sensually as she spoke, marvelling that _this,_ of all things, was what seemed to be affecting him the most, "… _You_ of all people should know that I like a challenge…"

Leaning forwards as carefully, Mikaela planted a quick, tender kiss to the top of the rig's rubber steering wheel before she took it between her teeth as gently as she could, pressing _just_ hard enough to keep him from moving but not so hard as to hurt him.

"What on _earth_ are you doing," he asked, almost as though he were dimly surprised to find her climbing on top of him or something, and not just biting his steering wheel. "Not that it isn't… not that it doesn't, ah, feel… _unexpectedly_ nice…"

Choosing not to answer, Mikaela used her free hands to wiggle her skirt all the way up so that a pair of pink cotton panties were exposed. Before she could lose control, her hands were back on the wheel and the gearstick and, breathlessly excited, she was upshifting, her head starting to spin as her heartbeat rushed in her ears. Not only was she aroused as fuck right now, but the adrenaline rush from the speed they were travelling at—and they weren't even at maximum speed yet!—was beginning to take its toll on her.

They were driving _fast._ But it wasn't fast _enough_ to get him off—just like the way the constant vibration of Optimus's sheer power was so, so good, and did _so_ much for her, it was not enough to get _her_ off, either. Oh, yes, doing this—driving fast—was _so_ exciting but if she wanted what she _dearly_ wanted, she was going to have to find a better way to close the link and _make_ the Autobot come.

Her hand was on the shifter again, right fingertips sliding up and down its length while she steadied the wheel with her left. "Tell me what you need," she requested, her voice a whisper, barely audible over the rumble of the Peterbilt. "Tell me, boss… what you want me to do…"

"Your—your hands, Mikaela." It wasn't just the radio that was flickering in time with his deep, resonating voice anymore, but every single instrument on the dashboard. "Your _hands_. They're soft—that's _good_ —"

Another wave of static rolled through the cab, and this time, she could pinpoint its source as being the shifter itself. And whatever that meant must have been good, because the Autobot _groaned_ then, for the first, real time—a very real, liquidy sound of pleasure that filled her mind with a blank, blissful kind of buzz.

"Oh my god, you like that?" she gasped, redoubling her grip on the shifter, hands sliding a little against it with sweat and then she realized that the moisture was even better for him—

"Oh, _primus_ , yes," he moaned.

She shoved the shifter into thirteenth, letting go of the wheel with her left hand, struggling to try to reach down to ease some of the aching tension she felt, too. But before she could do more than palm overtop the sensitive area on the outside of her underwear, the rig swerved right over the yellow line and it was all she could do to regain control again—which meant that any kind of self-administered relief was most definitely out of the question unless she wanted to risk their lives.

She sighed in frustration. She would have to just focus on _him_ , then.

" _Shit_ ," she groaned, mentally chiding herself. She just didn't want to let _go_ of him, not when she was doing so well that the staticky feeling was building strongly enough to make her entire arm start to tingle the longer she stroked him. "Errgh, why've you gotta have such a _huge stick_ … fucking hell, Optimus Prime—"

Even through his pleasure, the Autobot leader was surprised by the statement. "Nnngh— _is_ it? This is the— _ahh—_ small one…"

Mikaela felt her mouth open in surprise. " _No_ way."

"Oh, yes…" his voice was suddenly so gravelly and so deep that it took all of her determination to keep part of her brain that was concentrating on actually driving from crashing them. _Good lord._ "My _true_ form can be… much more— _nngh_ —impressive, in that way… even _if_ this one is capable of— _ahhn—_ um, capable enough."

" _More_ than capable enough, in my opinion," she sighed, her eyes half-lidded. "Hmm. Uh, Optimus, what are you _doing_ —?"

The Peterbilt had been moving without her noticing at first. The seat beneath her, as cushy as it was, had suddenly become even more soft and malleable, enough that she found herself sinking even deeper into it. Its intense heat enveloped her lower back just as she felt something semi-cold and metallic graze against her left thigh.

She jumped, looking down to see that her seatbelt had undone itself and had started to wrap itself around her upper leg, just as the right-hand seatbelt did the same thing to her right thigh. A startled-but-pleased sob wrung itself from her throat as she stiffened, biting down hard on her lip as she felt the two seatbelts gently spread her legs apart.

 _Holy. Shit._ Keeping her foot firmly on the accelerator, she allowed Optimus to tug at them, hardly able to concentrate through the haze that was filling her mind. _I can't believe he's doing this…_

"You have made me… _desire_ you, Mikaela," said Optimus, his voice so thick and husky, pitched so low that it was almost as though he was whispering right into her ear. "But I am not able to fully— _hnn_ —interface you, in this form… I will do the best I can…"

While he spoke, something else was happening. Mikaela felt her spine arch away from the seat of its own accord as the cushion below her started to move—part of it had risen into a solid little ball shape that rested precisely near a very sensitive place. She yelped, squirming, but the seatbelts Optimus had wound around her held her in place, gently coaxing her to slide forward a little so that the bump could make contact with the thin cotton outside of her panties.

"Ooh," she murmured as a surge of relief shot through her groin, making her back arch further still and her hips jut forward into it. The thing was _vibrating_ , vibrating at the same speed and oscillation as the huge semi's engine was, but in a much more intense, satisfying way—a way that tickled and teased and somehow had more 'life' to it than any other vibrator she had ever felt down there before. It was not an instantaneous rush like the one a typical sex toy would bring, but something hardly like a sex toy at all—it was slow and powerful and carried with it all the lust and passion of a partner who was enjoying pleasuring her.

"Jesus," she moaned, blinking lazily with half-lidded eyes while willing them to stay glued to the road, but the sudden, strengthening wave of static that was spreading from her hand's contact with his gear shift went all the way up to her brain and did nothing to ease the foggy blissfulness that was forming like a halo around her consciousness. " _God_ , that feels good." Her own voice sounded distant and unreal. _Fuck,_ he could screw her easily like this, if he had had the equipment—she was _so wet_ …

 _Focus,_ she told herself. If she wanted the Autobot to overload too, she was going to have to concentrate, no matter how hard it was. Breathing out a shaky sigh, she repositioned her hand on the gear stick, gritting her teeth as she accelerated and, with the pad of her thumb riding the edge of the shifter knob, slid the Peterbilt into the fourteenth gear.

" _Ahh_ —" Optimus's gasp was interlaced with static as Mikaela felt the shifter vibrate harder than ever, threatening to pop back out of gear. She recognized that right now, what the rig needed more than anything was a firm hand, and she was more than happy to supply it—she gripped the metal rod so hard that it hurt, forcing it to remain in place. "You must— _ohh_ —you must not _stop_ — _agh_ —!"

 _Click._

The small sound was noticeable even over the ever-increasing rumble of the Peterbilt's dizzying RPM, and so unlike anything else she'd heard so far that she found herself glancing down in time to see the little panel set into the top of the shifter's knob (the one inscribed with the gear numbers) eject itself to expose—well, whatever it was looked like some kind of—

—some kind of _port_ —

And as she watched, a part of it glowed, pulsating with a strange, blue light.

"Is that—?"

"Yes," said Optimus, totally breathless. "It is, of course… different in this form… but the function is… essentially the same—"

"Is that right?" Even through the haze of arousal and the mounting tension from that absolutely _distracting_ hard spot that was still hitting _just_ the right spot, she was curious. So this _was_ arguably a part of his reproductive anatomy, then, she thought, meaning the gearstick—and she'd had her hands on it all day, had she? Endlessly, endlessly teasing him along…

He must have really wanted it, then… but Optimus Prime had yet to do the one thing she was just _dying_ to hear him do.

She wanted him to _ask_ for it.

Continuing to hold the shifter around the metal shaft, she watched the Peterbilt's reactions carefully as she prepared to slide the transmission into the fifteenth gear. She gave the accelerator pedal a little pressure, testing him, and immediately the semi's tachometer needle spiked and the resulting flood of power bled straight through him and right up into her groin. The muscles in her legs tightened and she swore, leaning forward into the feeling before she regained control of herself again. Biting her lip, she tried to relax and stop straining against the seatbelts Optimus was using to hold her in place. _Damn it…_

There were only two more gears left. Somehow—amazingly—she willed herself to concentrate for long enough to slide him into the next gear, holding him tantalizingly softly and letting him _aaalmost_ pop the gear back out before pressing it fully in.

" _O-oh, oh primus_ ," gasped Optimus, and she knew that he was almost there. "I c-can't—you h-have to— _ahh_ —"

The little blue exposed port on the top of the shifter throbbed then, and she felt more of that tingly static race right up her arm. Simultaneously, the part of him vibrating so hard against her groin throbbed with it, too, and she outright gasped at the unusually pleasurable sensation.

"Fuck—"

There was no good way to describe it—it was the most amazing, tingly, _pulling_ sensation and she tensed in anticipation of the _zap_ she was sure would follow—what would it feel like? Would it hurt?—but whatever it would feel like, it did not come, and her body arched with disappointment as the sensation faded, wanting more. "What _was_ that?" she demanded breathlessly. "I had no idea you could do that…"

Optimus did not hear her. "Please," he was begging, and with an electric jolt, Mikaela realized that she'd finally gotten what she'd wanted. The Autobot's voice was breaking over the stereo, the ends of his gravelly voice overridden with interference. " _Please,_ finish this, Mikaela, _never_ before have I—I _needed_ this—! _Rghhh…_ "

The whole truck trembled with the depth of his rippling, frustrated growl. _Holy shit_ , she thought muggily, and a stab of something foreign laced through her—the Autobot's voice had been tinged with anger, and the notion that she'd driven him so far to the edge of reason that he was even losing control of his _emotions_ gave her a thrill of power that felt nearly as good as the vibrating seat did.

She was _so close_ herself… and, unable to resist any longer, she redoubled her grip on the shifter, summoning her remaining concentration to move the stick into the last, final slot. She felt the back of the driver's seat arching to press firmly against her spine as the Autobot tensed in expectation, aware of what she was preparing to do. The seatbelts wound around her legs tightened, too, pulling her downwards into the warmth of the seat, and she felt a shock of pleasure from the pressure he was applying crash through her.

Heat oozed through every inch of him as she shifted him—through the chair, through the floorboards, it bled through all the way past the sleeper in the back to the outside of the truck. The steering wheel, the dashboard, the gearstick—everything was hot and tense and vaguely, she realized that (not that she had actually wondered about it before) this was what it must be like to be inside of an Autobot's alt-mode before they climax. The instruments on the dash were going haywire, but with startled disappointment she realized that the semi had not actually gotten off yet.

 _What_? she thought, and then— _oh_!

The highway's yellow lines were a blur as she stomped on the accelerator, feeling her own climax come closer than ever before. _Fuck_ — _so close—_

And the Autobot shouted when she'd done it, when she'd finally realized what it was she had to do. She'd reached up with the pad of her thumb and rubbed it hard, right against that little throbbing blue node and the resulting cascade of static tingled and then she felt the _zap_ she'd needed, spreading straight out from her core in waves. The Peterbilt roared as the tachometer needle redlined, and she was slammed against the seat as the semi shot forward like a lightning bolt, twin flames of spark-energy trailing from each stack.

Fuck, it was like an orgasm but so much _more—_ everything was _him,_ the _feel_ of him, the _smell_ of him, the sound of his deep, resonating voice cracking as he yelled triumphantly, 'Ohhh, _Primussss_!' and she let go of the steering wheel, overcome.

She was dizzy—she couldn't breathe or see anything, she could not hear herself screaming—and through all of it they were still travelling at breakneck speed down this road, faster and faster with no one in control and it was a miracle they hadn't crashed already.

After what felt like eternity, it faded. Mikaela forced her eyes to open just in time to take the wheel before the entire rig veered off course into the ditch. Her heart hammering inside of her chest, she dared not touch the instruments inside of the cab that were arcing with residual energy—only once the white sparks had receded, and the tachometer needle began to settle down did she do anything besides guide him.

The truck began to decelerate. For a while, nobody said anything, and Mikaela watched, feeling drained and exhausted as Optimus manipulated the gear stick and pedals clumsily, finally bringing them to a rolling stop as he pulled over onto the side of the highway. She'd almost never felt so glad to be stationary again after such an absolutely wild ride. Her head was spinning from the rush of it all, but not in a totally unpleasant way—it was about ten times better than the best afterglow she could remember, but distorted, as though she'd just travelled through space and time to another motherfucking _dimension_ with the Peterbilt.

"Wow," said Optimus finally, his shaky voice still staticky over the radio.

"You can say that again," she mumbled with a sigh.

"You enjoyed yourself?"

"You better damn believe it," she answered, eyeing the Peterbilt's rearview with a wink. "That was… probably the craziest thing… I have ever done… in my entire life…"

Optimus chuckled, his gravelly voice sluggish and heavy with his own afterglow. "Indeed, it may have been inadvisable… but I think we'd both agree that it was worth it."

"Fuck yes," Mikaela answered, stretching and stifling a yawn.

"Though… I hope you will not be offended when I say that I would rather that I drove home without… assistance. I am feeling a little, uh—"

"Overwhelmed? Fucking _ravaged_?" she grinned.

"Yes, that," he said awkwardly, and she could hear the pleased smile in his voice.

"That's fair," she yawned. "I could use a nap, anyways, boss."

"There is a bed in the back if you would like…"

She listened to the sound of his engine as she climbed carefully over the center console and collapsed into the sleeper. It was as comfortable as she had hoped, and Mikaela curled up in the nest of blankets to let the post-coital exhaustion consume her as the rig swayed a bit. Optimus pulled off of the shoulder with the accompanying crunch of gravel under his tires.

"Incredible…" she mumbled drowsily, and the last thing she'd heard before she fell very deeply asleep was the Peterbilt's radio turning on to play a song, which Optimus quietly began to sing along to.

" _You say the weight of the world  
Has kept you from letting go  
And you think compassion's a flaw  
And you'll never let it show  
And you're sure you've hurt in a way  
That no one will ever know  
But someday the weight of the world  
Will give you the strength to go…"_


	11. Slow Down

**Redline**

.

 **Part 11**

She was awoken by the gentle rocking sensation of the Peterbilt pulling off of the main highway and onto a side street. The sun had sunk lower on the horizon and was now visible through the windscreen as a blinding lens flair, the colors of the landscape around them blending from the hot, arid, golden yellow browns of cracked dirt and the blue-greens of dry shrubs to a patchwork of light and dark as shadows appeared across the land.

The end of the afternoon brought with it a feeling of approaching serenity, like the sensation of slipping into a lukewarm pool on a hot summer's night. Mikaela yawned and sat up groggily, marvelling at how much colder the interior of the cab had become now that Optimus had had time to rest; stretching her arms over her head, she mumbled a satisfied little 'mhmm' before leaning lazily against the vibrating back wall of the truck's sleeper. She was so _comfortable—_ the events that had transpired leading up to her nap had left her with a fluttering, weightless, _satisfied_ sensation in her midriff that was better than even the best time she'd had with Sam.

 _God,_ she thought. He had been… _good._ It had been a lot better than she'd ever expected, which was saying a lot because they hadn't even technically had sex, had they? She hadn't even removed her clothes. It was incredible—and she couldn't help but wonder, if he was _this_ good while she still kept them on, what could the Autobot do to her if the situation had allowed for them to _actually_ fuck?

The thought was near-hypnotizing, but before she could think any more about it, Optimus had noticed that she was awake. "How are you feeling," he asked kindly, his voice rumbling through the truck and only adding to the fluttering feeling in her stomach.

"M'good," she answered sleepily, peering out the window to try and gauge how long she'd been out and exactly how far they'd travelled—judging by their surroundings, he had pulled them off of the highway and into some kind of ghost-town, but as for what time it was or where exactly they were she could not accurately guess. Waking up from afternoon naps was disorientating at the best of times—let alone after you'd just had an incredibly good time and fallen asleep in the back of a moving truck. "Where are we?" she asked him in confusion.

"I've taken us to the closest refueling station to base," said Optimus, his voice pitched low for her comfort. "I… thought it may be a good idea to, ah… …find sustenance…. for you, before returning to NEST."

Mikaela sat fully upright as Optimus rolled to a stop on the side of the road. Her stomach _was_ feeling painfully empty, now that he mentioned it. The hamburger at the diner with Bee earlier felt like literally ages ago, and while the fresh air, the rush of the open road, and complete insanity of having high-speed sex with Optimus _Prime_ had been super fun, the heavy adrenaline crash was leaving her feeling shaky and weak and she needed to eat.

"Mikaela?" asked Optimus again, his rumbly voice hitting an unusually high octave that caught her attention at once. He sounded nervous again, but as to why, she could not understand. She'd thought the Autobot would be over his nerves by now—after all, he'd basically just (little did she know) let her spend the past couple of hours stroking his _stick_ in more ways than one. "What do you say?"

Stifling another yawn, Mikaela undid her pony before sweeping her hair back into a messy bun, thinking. An absolutely ridiculous idea hit her—here they were, having just had accidental surprise sex together, and he was supposed to be taking her back to base; and yet he was asking if she wanted to stop somewhere for some food instead. Either Optimus was stalling for time for some unknown reason, or the Autobot was making a brave attempt to copy human customs and was asking her if he could take her to get _dinner_ —an act that in itself was innocent, but given what had just happened…

And besides, a simple glance out of the window showed her that they had hardly more than an hour left before the sun would begin to set and NEST's visiting hours would be over. Wasn't he responsible for making sure he returned her on time?

The more she thought about it, though, the more sense it made. It was something the Autobot leader would do—he was ever trying to understand the way the human race worked and she'd seen for herself that even the Autobots occasionally adopted said customs. She couldn't help but smile each time she saw it—there was just something endlessly endearing about it, especially coming from Optimus. It wasn't very often that one found themselves being asked by a giant alien robot if they could take you out for dinner, if that was indeed what he was doing.

Mikaela felt her face blush bright red as this occurred to her, Optimus remaining silent over the radio all the while. "U-um," she choked, flushing even deeper at how stupid her own voice sounded—she was normally really smooth and took being asked out in stride due to the sheer amount of times she'd been pursued by the opposite sex. But this was different—this was _Optimus,_ and there was just something _about_ him that made it so that it didn't matter _how_ long she'd spent around the Autobot or _how_ much sex they'd had together—he was always going to be able to strike a chord deep enough inside of her to render her momentarily speechless sometimes. _Especially_ when he went and said such cute things in that _voice_ …

Mikaela cleared her throat, unable to hide her own nervous amusement. "Uh, sorry," she said with an awkward smile. "But I gotta ask, boss—you're not asking me out to _dinner_ , are you?"

There was a semi-long pause in which she heard the hum of the Peterbilt's cooling system kick in—which was odd, considering they were stationary and the interior of the cab was already quite cool. The Peterbilt wasn't _blushing_ , was he?

"The customs of your species dictate that it would be… remiss of me not to make such a request," he answered, speaking slowly as though he were choosing every word carefully. "Especially not after… after we just, ah…" The sentence hung in the air between them, unfinished.

"That doesn't exactly answer my question, boss…" she said finally.

Another, longer pause. "…It was my intention, yes."

Mikaela was trying to control the surge of amusement that had her almost outright laughing at him. Unsure of why exactly she found this so amusing, she fought to answer him in a level voice, not wanting him to feel any worse than he already did. "I-I see," she coughed.

It was because of how _awkward_ he was about it, not to mention how downright crazy the entire situation was. It felt almost unreal. Not only had she just basically _done it_ with the giant Autobot leader, but _now_ he wanted to take her for dinner for good measure—if it weren't for the fact that the events were undeniably unfolding right before her very eyes right now, she'd never have believed it. It was _insane_ —and there were _so_ many reasons why she should have just said no and demanded he take her back to base straightaway. She knew she was in trouble as it was, and if they kept this up, then he'd be in trouble, too.

Mikaela chewed her tongue. Why did she have such a knack for getting herself into the most _unbelievably_ weird situations like this? It wasn't like she went out _looking_ for trouble all the time—it was that trouble always seemed to find _her._

But it could be so irresistible, sometimes— _especially_ when it was found in the form of one very reassuring, amazingly strong, stoic and _protective_ alien robot that had absolutely no right to be as attractive as he was.

"I would be flattered if you would join me, Mikaela, but if you don't want to…" his level voice cut sharply through her thoughts. "That is fine. I understand if you would rather to get back to your home. It is getting quite late, and NEST—"

"No," Mikaela interjected firmly before she could change her mind—a _dinner date_ with the semi was too huge an opportunity to miss. "No, Optimus, I think that's a great idea. It's Saturday night and it's not like I've got anything better to do—I'm totally up for a late night. That is, if we won't get into trouble…"

"I will send a message ahead to Ratchet to inform NEST officials that we will be arriving after visiting hours are over."

"And that's… not a problem?" she asked, blushing even harder because both the sheer _hopefulness_ in Optimus's voice and the idea of him informing the Autobot medic that he wasn't going to be back in time because he was staying out late with _her_.

Apparently he found something about this funny. Mikaela shuddered as she felt the depth of his laugh resonate inside of her chest. "You are forgetting who will be accompanying you, Mikaela."

"Oh, right," she said, feeling so stupid that she actually slapped a hand to her forehead. " _Duh._ Like they're going to have a problem with anything _you_ say. Okay, fine—I'm _starving,_ anyways. What's the plan? Where is it we're going, boss?"

No sooner was the question out of her mouth did she realize that there was a distinct problem with their plans that neither of them had mentioned thus far. If Optimus really thought he was going to take her out to dinner—and, judging by the very pleased growl the truck's engine made at her answer, he most certainly did—then _how_ exactly was he about to do this? While Bee could fit through a drive-thru, she very much doubted that Optimus would—did the semi perhaps have a holoform he could use to make it _appear_ that she had a date so that they could walk inside, like Arcee had used on her bike?

But before she could ask, the Peterbilt had pulled off of the shoulder and was making its way toward the only cluster of occupied buildings the derelict road-town possessed. "There is a place…" he reassured her, but left it at that.

"Okay." Mikaela trusted Optimus, and if Optimus was not concerned about it, she felt sure that she did not need to be, either. Climbing back up into the driver's seat inside of the moving truck, Mikaela had to grin when she felt the seatbelt slide over her automatically—he really could be a gentleman sometimes.

He took her to a place that contrasted so well with the nearby dilapidated buildings that the retro, immaculately-pristine diner looked so out-of-place that it could have been taken out of an alternate dimension and placed, smack-dab in the middle of the town and no one would ever have known the difference. Wild flashing lights hid the roof with a neon-rainbow display that made her eyes water and formed little trails in her vision as she looked away—great big spiralled letters spelled the word 'Nancy's', beneath which a solid wall of gleaming floor-to-ceiling windows showed an old-fashioned style parlour with bar which was, to her surprise, crammed full of people.

Likewise, while the derelict town's cracked and worn streets were empty, Nancy's front parking lot was full—every stall was occupied and there was hardly even room for a car to turn around.

"Optimus…" said Mikaela slowly, eyeing the packed interior of the diner worriedly as the Peterbilt drove past the main entrance and pulled into the back instead. "Uh… one question…"

"Yes?"

"How exactly are you going to, um, _have_ dinner with me, again? …There are a _lot_ of people in there…"

But the Autobot did not seem dismayed by this in the slightest. In fact, he'd sounded so pleased with what he said next she had to hold back another laugh. "You will see." that she found herself extremely curious.

She had to admit, she was curious. Optimus rolled toward the back corner of the parking lot, where there were more empty spaces. The rig was so large that he'd need at least four spaces in which to park. Going slowly, she felt him roll almost to a stop before a speed bump—which he crossed with a pained 'oof', and Mikaela thought she knew why. Even for a truck his size, the bump had been a little harsh.

This time, Mikaela was unsuccessful at holding back her laughter. "S-scrape your bumper?" she asked, gasping.

"Ah, no," said Optimus, still sounding pained but he laughed, too. "I am fine—just somewhat oversensitive."

"Oh my god," she coughed, trying to regain control. "I am so, so sorry for laughing—it's not funny. I mean… okay. It's _pretty_ funny. But not because it hurt. But—now I _have_ to know—is this a common thing—?"

Optimus let her giggles subside before he answered. "No, it is not common… but it can happen. Usually it does not unless I am injured, but sometimes, ah…" he paused, and when he continued she had the impression that he was being seductive on purpose, his voice pitched ever so low and gravelly, "Sometimes, when I have been _handled roughly_ …"

Mikaela felt the blood rush to her face faster than blinking. "Oh god… I'm sorry…"

"You do not need to apologize. I did not say that it was an _unpleasurable_ experience."

Suddenly, the cab of the Peterbilt felt boiling hot. "Oh Jesus," she groaned, but her chance to respond in kind was lost in the hiss of air brakes as the semi parked, and she'd looked up at the backside of Nancy's (which was thankfully a lot less lurid than its front had been) to find that the restaurant had none other than menu boards plastered to its siding.

"Ooh!" gasped Mikaela, finally understanding—Optimus had taken her to a _drive in_! "I get it—haha! You're probably not going to believe me, but I've never actually been to one of these!"

"Have you not?" asked Optimus as he shut down the idling engine, sounding confused. "I believed this was something of a habit for your kind, to be served sustenance—"

"What? Not restaurants in _general_ , silly," she tapped the dashboard, shaking her head with a chuckle. "I mean a _drive-in_ one."

"Oh," said Optimus in embarrassment, catching on. "Yes. …Of course."

"But are you sure they serve trucks?" she asked, looking around the parking lot—none of the other cars parked in the designated spots were rigs like theirs.

She could tell that Optimus's embarrassment deepened, but his voice was level when he spoke. "Hm. I am not positive of the required specifications, as I have not had a companion to try this with before... You are the first, Mikaela."

The amount of emotion the Autobot had managed to put into every syllable of this sentence hit her so hard and so suddenly that she was speechless. His gravelly voice had carried with it not only the sheer gratitude the semi must have been feeling toward her after the adventure of a day they'd had together, but also an undertone of affection. It made her remember exactly how lonely he'd admitted to being, and with a pang, she reached forward and rubbed the dashboard in what she hoped was a soothing, comforting kind of way. It was warm to the touch.

"Thank you," he rumbled.

She was saved from having to reply by the arrival of the drive-in's server. The tall blonde boy must've been about her age, Mikaela thought as she watched him eye the massive Peterbilt, carrying a notepad and wearing a teal apron that clashed horribly with his pale-orange shirt in typical retro-diner-aesthetic. His neon-orange nametag read 'Spence'.

Spence stopped beside the driver's door, and Optimus wound down the window so that she could talk to him automatically. "Hi," she said, forcing a smile.

"Hi. Nice truck," he smirked, eyeing the vehicle again before looking back up at her. Mikaela felt a far-too-familiar creeping sensation as the boy stared at her just a little too long for her liking.

"Thanks," she said coolly, forcing another smile before adding in a far more serious voice, "It's, uh, it's my _boyfriend's_ truck..."

She'd said this calmly, meaning to put to rest any possible _ideas_ this guy might have been having about such a very attractive young woman sitting inside of an equally attractive Peterbilt (seemingly) by herself, before he did something stupid and embarrassed her and Optimus both. It was a technique she did without thinking a lot of the time, because it was more often than not that boys expressed interest in her—although, this time, she had forgotten that Optimus had obviously not been aware of any of this. Unable to voice his surprise over the radio without revealing himself, he had accidentally triggered his horn in his alarm, making Spence jump about a foot and almost fall over himself.

"What the hell!" he yelped in annoyance. "What was _that_ for?"

Mikaela tried to act natural, hitting the top of the steering wheel hard with her palm as she cleared her throat. "It's nothing," she said. "Slipped."

"Right…" said Spence, once again eyeing the truck, only this time with suspicion. "Anyway, I just came over to tell you that we actually don't service semis here… Most of the girls refuse to hand the orders so high up."

Mikaela's face fell and either she was imagining it, or Optimus actually sagged a couple of inches on his suspension. "Oh… okay." _Damn it,_ she thought to herself, flashing the server her best puppydog eyes. _Well, at least we tried._ "I guess I'll just—"

"Wait."

He seemed to be trying to make up his mind about something, and for good measure, she flashed him her biggest smile yet, showing both rows of her perfectly straight, white teeth while she leant partway out of the window. "Yes?"

"I'll make an exception. _This_ time. But only because you've got such a nice truck…" he said grudgingly.

"Sweet!" she cheered, and proceeded to order a chocolate milkshake and another hamburger with fries while her stomach rumbled at the mere mention of the food. It wasn't until the server was gone that Mikaela realized—she didn't know if the Autobot had anything of his own to eat! Or if he even _could_ eat anything except energon, for that matter—Bee had always been able to take care of himself, so she'd never paid much attention to what it was the Autobots actually ingested for energy besides their specific brand of fuel. She supposed perhaps water or some other kind of fuel by-product would be compatible with their systems, if anything.

"Shit, Optimus, I'm sorry," she apologized. "I forgot—you're probably starving too, and they don't exactly sell pints of energon here—"

"It is all right." His voice was amazingly calm and soothing and immediately made her feel silly for feeling so bad. "I will refuel when we get back to base."

"Okay," she said, not fully believing him but accepting his answer nonetheless.

It was only a couple of minutes until Spence was back, carrying her drink on a small platter in one hand and a very long, polished plank of some kind of fancy dark wood in the other. As he approached she could tell that it was some kind of extended tray fitted with a bracket on each end, which he balanced perfectly, hoisting one end up to her. Mikaela dextrously slid this across the cab with one hand, relieved when Optimus caught on quick and unrolled the passenger window so that she could push the board into position.

Spence then handed her her milkshake, which she accepted happily and took a sip from immediately before licking the whipped cream from her lips and placing it down on the tray.

"Thanks," she said gratefully.

"No problem. I'll be back before too long with your order."

He then handed her some cutlery neatly rolled up in a napkin, and left.

"…Why did you tell that human that this truck belongs to Sam?" Optimus asked her as soon as he was out of hearing range.

Mikaela had to suppress a snort, wiping more whipped cream off of her lips. It was an honest question, but the innocence implied behind it was almost absurd if you forgot about the fact that it was coming from an alien robot that was still somewhat naïve when it came to the ways of humans.

"He was attracted to me," she said plainly.

"And why does that mean that I have to belong to Sam? Why could you not say that I belong to _you_ instead?"

Mikaela was confused. "Did it really bother you that much?"

"No, but…"

She shrugged. "Power of suggestion, I guess. If he knows I have a boyfriend, he'll be less likely to hit on me or something weird. …I hope."

"Oh," Optimus rumbled. "…I see."

"But that didn't stop him from changing his mind about letting us stay," she smirked, taking another sip.

"Do you think that was why he reconsidered—because he thinks you are attractive?"

Mikaela frowned thoughtfully, wondering if Optimus would react positively to her answer or not. "I don't _think_ so. I _know_ so."

Sure enough, the strength of his response surprised her even though she _had_ figured it would irk him because, well, that kind of thing was just generally not his way. As the leader of the Autobots, honesty and integrity were things that Optimus Prime valued very much, and he did not always take kindly to the idea of rule-breaking.

The Peterbilt shook with the Autobot's sound of annoyance. "Absurd," he growled. "…Not that I am disappointed…" he added as an afterthought, trying not to offend her.

"Neither am I, to be honest. It worked out pretty good for us."

"Indeed."

Another awkward silence stretched between them. It was amazing how just a couple of hours ago, they'd been talking what felt like nonstop—but now, the overwhelming notion of what they had done together and what it all would mean once they got back to their regular lives was beginning to sink in. Mikaela had the distinct feeling that the 'bot was every bit as uncomfortable with bringing the subject up as she was, even if it was technically in their best interest to discuss it while they still had the chance.

"Um," she said at length, her voice hitched a little higher than normal. "So…"

"Do you encounter this problem a lot?" asked Optimus very suddenly, and at first, Mikaela was confused as to what he meant.

"Hm?"

"The boy," the semi clarified. "You said he found you attractive and that it was a concern because you are with Sam."

She breathed deeply, thinking about it hard. If she was honest, the answer was yes. Boys _never_ wanted to leave her alone. Simply put, Mikaela was an extremely conventionally attractive young woman, and she suffered from everything that went hand-and-hand with it—meaning that sometimes, she happened to attract _too much_ attention.

It was another part of why her and Sam's relationship was so rocky these days. Mikaela had never given him any reason to doubt that she was loyal ( _ha, except now_ , she thought, and the unwanted feeling of guilt pooled in the pit of her empty stomach), but he was very aware of how other men looked at her, and there had been times where, no matter how hard he tried to hide it, she could tell that he was very jealous.

"Yeah," she answered finally. "Yeah, you could say I encounter it a bit."

It was the Peterbilt's turn to think hard. "And you have not once…" he said quietly. "You have not…?"

Mikaela immediately understood. "No."

"Never?"

"Never. Well… until now…" she mumbled, hating herself for saying it aloud.

"…I am sorry."

And _god_ , did he sound it. Mikaela felt her stomach plummet even further. "Don't be," she tried to reassure him. "Don't worry, Optimus. Honestly, I already told you… I _wanted_ this."

But the poor Autobot was still very obviously confused by the entire situation, and she could not blame him. "But you are _with_ Sam," he said.

"I know," she sighed.

"Then … _how_?"

Mikaela stared out the window. How was she going to explain it to someone who's biological programming just didn't function the way hers did when she couldn't even understand _how_ hers functioned in the first place? Because Optimus had a very valid point, and one she couldn't even come up with a good answer for herself— _how_ had this happened?

"I don't… I don't know," she sighed finally. "I guess… well, it's like I said earlier. There are a lot of reasons… like, Sam's going to college and I'm going to be stuck here working this dead-end job all by myself. And taking care of Cal… I don't know! I kind of really think our relationship's pretty much already over, to be honest. It wasn't something… that was good enough to stand in the way of, uh, this. Unfortunately. If that makes any sense… "

This information seemed to cheer Optimus up somewhat. "So you did not have… intensions of being bonded—?"

"I— _what_?" she cried, caught off-guard. "You mean like, _marrying_? _God_ , no. I'm way too young to get married, and besides, Sam hasn't even got the balls to tell me he _loves_ me..."

She actually felt the semi perk up. "That is good for us," he said before adding guiltily, "For this situation, I mean."

"Yeah, don't sweat it. He hardly even acknowledges my existence anymore."

A long pause before Optimus said gravely, "That is terrible."

"I guess you weren't the only one who's been feeling lonely."

But at that moment their conversation was cut short by Spence returning, this time bringing a plate containing the huge hamburger she'd ordered and a steaming serving of fries. Absolutely ravenous, she picked up the burger immediately and began to eat, too hungry to even be embarrassed about how its sloppy sauce dripped down her fingers and hand and onto her plate.

"That looks…" said the Autobot, "…Exquisite."

She couldn't tell if he was kidding or not.

"It ish," she said, her mouth partly full of food. She swallowed, and then took a sip of milkshake. "Mm."

"What is it like?"

"What's it taste like, you mean?"

"Yes."

She picked up a fry, studying it before biting off the end. "Salty… greasy… _dreamy_. So, so good, but so _bad_."

"How so?"

Mikaela laughed. "Not good for the waistline. _Really_ good for the mouth," she winked. "Speaking of—what's _energon_ taste like, then?"

"Hmm," the semi rumbled. "It is good."

"That's it?" she asked, taking another bite. "Itsh not like, tangy? Or shalty? Or," she swallowed, "Sweet?"

"It depends," he answered, "On what kind. High-grade is more concentrated, and bitter—whereas its opposite, low-grade, does not really have a taste, but in a good way. It is the simplest form of the substance that we can still derive energy from."

"So like…" she thought for a second, "Low grade is like water? For us, I mean?"

"That is a fair comparison, yes. But you also require additional sustenance."

Mikaela finished the last of her burger and fries and cleaned off her hands, sucking each finger before wiping them on a napkin. "God, that was good," she leaned back into the seat feeling a _lot_ better. "I'm super glad we did this, Optimus."

"Really?"

The undertone of genuine disbelief in his voice tugged at her heart. " _Yes_ ," she said, her usual gusto back in full force now that she'd eaten. She slapped the dashboard. " _Seriously!_ You've gotta stop doubting that, boss. You're a pretty great 'bot to hang out with—um, for a kind of grumpy old guy, anyhow…" she laughed.

Optimus chuckled, too. "That," he said, his voice dropping an octave or two as he rumbled lowly, "Is _not_ me. _That,_ is Ratchet."

"Oh my god, you're right!" she giggled.

"Only, it may be best if you did not tell him I said that."

They laughed together, and then silence fell, but it was not the same kind of guilty, awkward silence as before. It was a happy, peaceful silence, a silence filled with just how genuinely thankful the two of them were to be in each other's company, and to have had each other's company throughout the entire day.

It was Optimus who broke it first.

"I am glad we did this too, Mikaela," he said, his voice warm over the radio.


	12. Stop

**Redline**

.

 **Part 12**

By the time they had arrived back at NEST, the sun had sunk well under the horizon. The sky to the east held only the faintest line of bright orange, which glowed against the Peterbilt's custom flames making them appear to burn brightly and flicker almost like real ones. The heavy chrome visor, endlessly tall stacks and pristine windshield were all smooth sheets of silver, reflecting just as impressively as ever under the first winking stars of the evening as the truck rolled along slowly, dawdling.

It was the stars that she watched, shining like little, twinkling holes cut in periwinkle-blue; she tried to make out patterns, catching only the faintest outline of the big dipper. When she had been a little girl, Cal used to tell her to choose one and make a wish for something that she hoped to someday have come true. Drawn to the brightest star hovering directly due-west of their position, Mikaela let her eyes slide closed as she breathed in the scent of the world that was wafting through the Peterbilt's open windows—the weirdly addicting odour of cooling asphalt mingled with the potent smell of drying sage and dust—and wished that someday, she would see Optimus Prime again.

That was the most beautiful thing about a wish, that it was private; a personal, intrinsic desire laid bare to no one but the wisher themselves, unless the wisher should choose to divulge the content. And so, such things had a knack for being unbiased and honest beyond all else, an unwitnessed expression of the best-kept secrets of someone's soul—and it was her soul that wanted _him_ , in that moment, more than anybody.

The thrill of him, the _smell_ of him. It was so much more addicting than she could ever have imagined and briefly, images of them, _together_ , passed through her mind—whether it was because of the aftermath of the day's events or something else, she did not know.

She fantasized about him—him charging into battle, blue eyes blazing with white hot rage. Him, towering over her, his magnificent body ever so solid and stoic and _safe._ And her, _with_ him—her being the only human alive who lived to tell the tale of his momentary weakness, the only one capable of bringing the Autobot leader to his knees. Their shared experience had been so lovely and intimate and sweet, and it made her imagine _more_ ; what would it be like, to enter a real, sexual relationship with him?

"You know," Mikaela said finally, her heart hammering in her throat at the thoughts that were passing through her mind, her eyes staring unseeingly out the windscreen as the Peterbilt meandered, ever-so-slowly, toward the airstrip. "Cal used to tell me, as a kid… if you make a wish on the first star in the night sky, it'll come true."

When Optimus Prime answered her, his voice was so level and calm she felt some of her inner turmoil and excitement melting away into serenity on the spot. "And have you made one?" he asked.

Mikaela remained silent, thinking deeply. It was so hard to make sense of everything. It was so _confusing_ , having found herself in a situation that was effectively tearing her heart in two—on one hand, she loved Sam deeper than anyone, and she had shared more hurt and been through more battles with him than anybody else alive. But on the other, her newfound feelings toward Optimus were so disconcerting and complex and _powerful_ that she knew it was going to take a long time for her to sort them out.

A long time, in which she knew it would be better for them to go their separate ways, at least for now—she had a life at home, with Sam, just as he did at NEST, with the Autobots. They both had important roles to play in those lives, and weighty responsibilities—there was, simply put, no alternative way for the two of them to run off together, or something unreasonably stupid. Not now—not _yet_ —at any rate.

And so, her answer to the Autobot's question came to her very slowly and very painfully. "I did," she said, her voice uncharacteristically quiet and serious as she debated whether or not she should tell him what her heart wanted at all. "…I wished that we could do this again someday," she told him sadly.

The cab of the truck was so silent that she could hear the rough peeling of the fresh pavement sticking to the bottom of the Peterbilt's tires as he drove. The silence was heavy, the significance of her words hanging in the air between them—she felt the rumble of the Peterbilt's engine and the gentle swaying of the truck and she knew that he, too, was recalling how she'd refused to let go of his steering wheel the entire ride back. The sensation of his gear stick knob vibrating under the palm of her hand was still fresh, as was the thrill of the endless expanse of asphalt rolling under his tires. It had been hot and blazing and full of some kind of weird chemistry that neither of them could explain or wanted to let go of, exactly.

Breathing in deeply, she drifted away in his heavy, masculine-mechanical scent. How she'd miss this, this smell, and _him_ —would a shower wash it all away? Or would it cling to her so strongly that she'd notice him on her for _weeks_?

And how could she find satisfaction, driving another vehicle after these events—even the heady vibration and quick acceleration of her motorbike, Valour, so amazing not one day ago, could now never compare with the rush and sex appeal of the rumbling Peterbilt and break-neck-speed sex that went along with it. It was hot and reckless and oh-so-good and life was going to be so _boring_ without him.

"Do not be sad, Mikaela," said Optimus finally, and she felt the seatbelt restrict across her chest briefly in a comforting hug. "But I think that, for the time being, we have reached a crossroads; we are at war, and your race needs me, just as Sam needs you. Until the day comes where that is no longer true, you must be there for him—just as I must be there for my Autobots, as it is my duty to lead them into battle."

Mikaela sighed deeply, taking only a moment to marvel at just how _noble_ the semi had sounded. "I know," she muttered.

"I apologize again." His rumbling voice was heavy, and through the window she watched with reluctance as the Autobot Hangar loomed ever-closer, its bay doors thrown wide as its cheerful light spilled out onto the darkening airstrip. "For it is not the way of a Prime to seduce a young femme whose spark— _soul_ —belongs to another. I believed that I, above all, was capable of resisting the desires that the delicate touch of such a wholesome soul is able to bring out in my kind—but I was wrong. Even a Prime has a weakness, Mikaela."

Mikaela felt her stomach somersault at these last words. "Your weakness is _me_?" she asked, astounded.

"It would seem so."

The gravity of his confession had made her mouth dry. "G-gosh, Optimus…" she stammered, blushing.

Darkness had almost fully fallen by the time the pair had reached the large, flat space of blacktop just outside of the Autobots' home. Optimus parked and cut the engine and over the hiss of his brakes she could hear the merry sounds of their comrades' laughter wafting through the open bay doors, and even as she watched she saw Bee trying to free himself from the group so that he could come get Mikaela, but Sideswipe and Ironhide wouldn't let him leave.

The sight of something so _normal_ happening seemed so _odd_ after such a wild day. It was hard to remember that things like Bee's silly personality and her warm, comfortable bed back at Cal's place still existed. "Looks like they're having fun," she said, smirking in spite of herself.

Optimus chuckled. "Yes, I think they are."

She watched Bee hit Sideswipe on the arm, gesturing to the awaiting semi-truck, and her nerves flopped unpleasantly as she thought of what Bee would say if he knew what it was the semi and the human girl had actually been up to. Bee wasn't the kind of person who would take lightly to such a thing—as most of the 'bots were, he was very loyal. _Especially_ to Sam. "You won't tell them, will you?" she asked Optimus, suddenly stern as worry pooled in the pit of her stomach. "About what—uh, about what happened… earlier… right?"

"I will not, if that is what you wish," he said, just as calmly as before, but Mikaela still felt obligated to reassure him that her request had not been out of anger or shame in what they'd done. She wanted to protect the relationship she had with the other Autobots very much and was concerned that if they found out, they would blame her for seducing their boss on purpose, or something. It was a horrible thought, and for some reason, she just couldn't see that going over too well with all of them… "Please don't—I mean," she started to explain. "It's not that I didn't like what happened, it's just… me still being with Sam, and all… I don't think it's a good idea, to uh—"

"I understand," he rumbled over her, before adding in his most reassuring voice yet, "You have my word." She knew immediately that she did.

That was a very beautiful thing about the Autobot leader, thought Mikaela. It was not only his incredibly deep, soothing voice that made him feel undeniably trustworthy, but nothing less than nearly every single one of Optimus Prime's traits that actually made him so. And with this power, he set her mind at ease much better than any human or Autobot in the entire existence of Earth could have, and she felt her middle unclench involuntarily.

In the distance, she saw that Bumblebee had transformed—the black-and-yellow Camaro was coasting slowly toward them, flicking on his headlights as he went. The dark expanse of asphalt in front of them was bathed in white light as the Camaro's horn beeped twice in greeting—Mikaela waved at him enthusiastically out of the Peterbilt's window, just as she felt Optimus undo her seatbelt. It was a silent cue for her to start saying farewell.

All she had time to do was to plant a single, swift kiss on top of the steering wheel as stealthily as she could before she was opening the door and stepping out of the cab. Out of the corner of her eye, she could have sworn she'd seen the rig's highbeams flash on once of their own accord—whether in response to her kiss or as a silent greeting for the Camaro or both, she did not know.

It was no sooner than she'd jumped off of the Peterbilt's last step than she'd heard him transform behind her. She turned around in time to see the huge shape of the Autobot leader straighten, his true form lit by the light streaming onto the tarmac from the Hangar and Bee's white LED headlights. Craning her neck to look up at him, Mikaela's eyes widened, taking in the way his armour reflected like one-million little shining stars blinking back at her as he stood, ever so tall and regal and important—

"Optimus?" she asked before she could think twice, her voice so quiet that she was momentarily worried that it wouldn't make it up to the tall 'bot's aural sensors.

"Yes, Mikaela?"

She had looked straight into his optics as he spoke, and she thought she had seen something crackling behind them, like some kind of residual energy from his spark. "Another time, right?" she asked as vaguely as she could, watching him closely.

She was sure of it, this time—his optics had flashed brightly and she felt the blazing energy behind them burn straight into her own eyes.

"Another time," he echoed, his resonating voice vibrating the very air molecules around them as it penetrated straight into her heart.

He then looked up to the sky, and she followed his gaze, suddenly overwhelmingly conscious of just how crushingly huge the near-infinite mass above them was. The weight of everything that came along with the knowledge of what existed up there was heavy on her—the lives and the sparks of so many 'bots and the legacy of their ruined planet, Cybertron—and she felt herself become dizzy with the significance of it all.

Staggering slightly, she felt her way over to Bee. "'Bye, Optimus," she said finally, grinning wistfully as she patted the Camaro affectionately on the hood. Bee swung the driver's door open for her with a happy wobble. "And thanks again!"

"You are very welcome." As she looked back, she saw the Autobot leader transform one last time, back into the majestic Peterbilt—his blue accessory lights blazed neon-azure just as brightly as his optics had. The truck's engine shuddered into life with the now-very-familiar diesel growl, and Mikaela couldn't help but smile with butterflies as she slid into Bee's driver's seat and habitually slung the Camaro's seatbelt over her shoulder.

"So, how'd it go, babe?" Bee asked her, cheeky over the radio.

"Oh, you know," shrugged Mikaela, grinning as casually as she could while still eyeing the Peterbilt's gorgeous form through the windscreen. "About as much fun as you'd imagine hanging out with a grumpy old semi-truck all afternoon would be. How'd things go for you?"

"Same-old," Bee laughed back at her before emitting a sad little whine. "I got some bad news, though, Mickey. I ain't gonna be in town for your birthday."

"Aww," she hummed back, simultaneously disappointed and vaguely surprised at the same time. Having half-forgotten the entire reason why Bee had brought her out here to visit the Autobots in the first place, with a jolt she remembered that in only a weeks' time, she was facing a weekend entirely in Sam's company.

 _Yikes,_ she thought.

"Yeah," continued Bee. "Got'a few more raids to-do. Lotsa 'Cons 'round, and now they're saying they want'a send us to _China_ next month _._ Somethin' about _Shanghai…_ "

But Mikaela wasn't listening. As the evening deepened, it made the world around her feel unreal—while the infinite cosmos stretched out forever above them, it made her so aware of just how tiny she was and how relatively huge the roll she'd played in the universe's recent events really was.

It could be so confusing—half of her just wanted to be _normal,_ but the other half could not rest, now that it had discovered the world of the Autobots and the existence of the war they waged on the Decepticons. How could she truly go back to her life, now that she knew about how much was _out there_?

A laugh track played through the radio just as Bee's engine turned over, startling her out of her revere. The Peterbilt's headlights turned on in front of them and Mikaela was momentarily dazzled by the vibrant display. Taking this as an invitation, Bee lurched forward and revved, spinning into a beautifully-controlled drift as he did two full donuts around the parked semi, tires screeching. Mikaela felt laughter bubble up inside of her despite how solemn she felt and she screamed joyfully, rolling down the window to breathe the tantalizing scent of hot sage and asphalt.

She waved at Optimus one last time; then, Bee swerved sharply and sped off toward the horizon, honking once more in goodbye—Mikaela watched the semi in the rearview as a loud double-blast of the rig's air horn echoed endlessly through the muggy evening air. Two twin trails of burning-red tail lights and a line of dust were the only things the yellow Camaro left behind on the tarmac.

And it was through the very last vestiges of light that the two home-bound companions sped toward the NEST main gate; watched only by a solitary, custom Peterbilt truck. Optimus Prime stayed there, alone, forgetting that he was still in alt-mode long past when they had disappeared from sight—he stayed there so long that the sky overhead had turned from indigo into inky black and the few stars blossomed into trillions and the milky way arched overhead in a long, hazy line, thinking to himself—

He thought about Bumblebee and Sam and Mikaela, and all of the things that were in store for them all, the good and the bad—

He thought about the Decepticons, and how they were living through what he had hoped was no more than the last wave of the fight, but what was more likely only a brief calm before another inevitable bout of war—

And he thought about the sheer, wholesome beauty of planet Earth, the sun and the stars and the innocence of its good people, and about how he was now the only leader who could protect them from the coming storm—

*~\\\\\\\\\\\~*

THE END

*~\\\\\\\\\\\~*


	13. Addendum

Addendum:

When I originally finished this story, I had -promised- to attempt to start writing its sequel. Well, it's been nearly half a year since then - and I've only just now realized that ffnet, unlike ao3, has no real way of easily finding a fic's sequel unless you're tracking their account. So I'm adding this here as a way for anyone who reads this in the future/has read it in the past to find its sequel(s) more easily:

Currently I'm in the process of writing ONE (out of two planned) sequels, titled **E-Brakes On** (you can find it under this account). It is heavily a WIP & my life does not allow me much time to write anymore, but I do plan on finishing it someday - so if you liked this fic, & are craving some more Optimus/Mikaela shenanigans, you can now head over there & read a little more of them. :)

Thanks again for everyone who fav'd/reviewed this story, & hopefully I'll find the time to write/post a new chapter of E-Brakes On before the new movie is out ;D.


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